Its hard to tell but I think you may misunderstand the description of the stock in the book. Before I go into why, part of what makes me believe Erdnase was a cheat from reading this move in particular is in the following phrase:
"We term this example a fancy stock, as it is very rarely that an opportunity occurs for selecting three sets of Four of a Kind; but the procedure is the same for two sets, or for sets of three, or pairs, or, infact, for the stocking of any number of kind, with sleight variation in the calculation."
In this I see the point being made that the opportunity to obtain this four of a kind being rare, but more so that he knows that the opportunity to do anything with it is also a rare event. On the surface I can see why someone would think that the move (if used directly as the example Erdnase uses to teach the move) would only be of use for a show of skill.
Erdnase says that he knows the event occurring to be in a position to do this is rare, he knows from card playing experience that getting three sets of four of a kind in order to the top of the deck isnt an easy feat. From his words about the procedure being done with lesser amounts of cards of kind I also believe he knew that being in the event to use such a thing is also rare.
The following is partly why Im not sure you are getting the text right:
Its in your mention of the bottom of the deck in your last post; the bottom of the deck never comes into play.
For a moment Ill hypothetically assume it is to be done with three sets of four of a kind in the desired order and for five players, Ill also hypothetically assume they have been culled to the top in the desired position.
There is no need to get the winning hand (or any known cards) to the bottom, the idea is that all three sets of four sit on top of the deck, they are stocked in relation to the top and the winning hand is dealt to the dealer leaving the other two sets of four as the new top cards of the deck ready to do as the dealer pleases on the draw.
To take the move further than the books example; and Erdnase clearly knew this was possible. It would take a book of its own to cover the true possibilities of his stock shuffle:
To use the twelve card fancy stock in a five handed game (or any handed game) doesnt necessarily mean culling (by whatever means) three sets of four of a kind to the top, there are many variations of sets of four, three, two, sets of three and two or even a large stock of no particular numbered sets.
This will come clearer as you read but the reason being is that the sets of two, three or four dont even have to be of kind.
Imagine you gathered the cards ready for the deal memorising the order of the top eight cards of the deck.
You do the twelve card fancy stock and deal, you know none of the cards in the other players hands or in your own hand (until you look of course) but you do know the top eight cards of the deck before you go into the draw.
Many a successful card cheat has ruled out the need to stock and this is partly due to the need to cull ready to stock. They may use marked cards (edgework, pegs etc.) or glimpses to get the information thy need and that this stock offers. So this stock used like I said above then offers this information with no need to glimpse and with no work in the deck.
Playing regularly, with no mechanics other than this shuffle, offers a massive advantage that couldnt be beaten by straight play. If you add a second deal or if you were to add a cull it can of course be more powerful. Im sure the second deal speaks for itself, as for the cull, and for illustration purposes:
You cull four aces and have them as the lowest set of four in the twelve, the top two sets of four are just sets of four for the purpose of describing the move. They are in-fact eight totally random cards, these you memorise as in the previous example. You do the twelve card fancy stock getting four aces on the deal and also knowing the first eight cards going into the draw.
A card player reading the description of this stock can instantly see this advantage and can instantly see that the three sets of four is just the surface. Im pretty sure Erdnase (as a card player) would have known this when writing it.
Of course, if you are playing at a game where you can get away with dealing yourself four aces there is little need to know the draw cards. As Erdnase did with the stock in his book, I have only used it to illustrate the procedure.
The example before that one was of course one of actual use, as is the above one but with different cards, perhaps like the following:
On gathering the cards you see a five of hearts, a six of clubs and a seven of spades, all sitting nicely beside each other. Within the distance of the next nine cards is a four of clubs and an eight of diamonds (not necessarily beside each other), you just have to position the three beside each other to be part of the lowest set of four and remember the positions of the other two that lie within nine cards (above) and shuffle as though you are stocking twelve for three sets of four (or three sets of three if they are within six cards) and you get your five, six, seven on the deal and know the positions from the top of the deck for the other two cards of your straight.
As for a cold deck being a better and easier move, it certainly isnt better and Erdnase states quite clearly his thoughts on that and the easier issue:
Of course an exchange may be made by sleight-of-hand, but the player who can accomplish this feat successfully is generally well versed in the higher orders of card-table artifice, and will dispense with such make-shifts as cold decks or any kind of prepared cards.
I agree with him.
If you read through the description again you will also find that there isnt really any mention of setting up a cooler on a mark. The closest that comes to it is:
If the dealers set is the highest of the three it matters little to him how the draw is made, as none of the players can get a higher hand.
All it really says is that its a stock to get the dealers hand to the dealer and the other cards on top of the deck for the draw to do as suits the situation best.
I can easily see that with the mention of three sets of four of a kind at the start, and then with this statement at the end it could look to some that perhaps it is a shuffle to deal three people all four of a kinds or something similar.
As with the book itself; it is way deeper than just that, part of the beauty of every aspect of this book is what lies beneath its surface.
As for Erdnase needing the money, I dont particularly take this seriously. It could be a sarcastic joke or something as mentioned by some. I even remember once when I started to write a book, the amount of money I thought to be involved was massive compared to what I later found out to be the reality, it was a gradual decrease of expectation along the years of writing.
I dont think the statement can be one to be taken as proof that he wasnt a cheat.
Anyway, I think the devil wrote it, he must still be making money off it.