Be Honest Plus
Here's a four-phase (let's give the Rule of Three a little nap) transposition routine that gets good responses. Delete patter as you see fit.
Short Form 1040 E-Z:
1. Double Lift, 2. Two-Card Monte move, 3. Fechter's "Be Honest, What Time Is It?", 4. Top Change of two for two.
1. Spec shuffles ("Just don't get them out of order.") and returns deck ("Okay, are they in the same disorder? Good.") You cut the Face-Up deck wherever there are any two red cards (Let's say the 4H and 9D. No, maybe the 10D. No, I guess the 9D is okay this time.) at back of deck followed by any two black cards and rest of deck. Turn deck FDn with reds on top. While pattering about "those card cheats" and how they (you! hee hee!) "switch the cards", you double-lift to show the 9D but actually put 4H onto table or put table underneath motionless 4H. Then single-lift (Marlo method three) the top card of deck to show "the other card we'll use, the 4 of H ... No, it's 9 of D again! Then card on table must be 4 of H!", you gasp, coming THIS close to nervous collapse.
Confess to spec that this is the very Card Switch that you were just talking about, and that you'll show it to them a couple more times so they'll know what to look out for. Tell them that your middle name is Helpful, and that you had it legally changed from Alan.
2. Explain "in very general terms" that you started out "with the 9D on top of deck in LH, while the 4H was over here" in your RH. During this patter, do the Two-Card Monte switch (Walter Gibson's?), actually depositing the 4H, not 9D, FDn onto deck in LH.
(Basically, you hold the two cards FU at fingertips of palm-up RH, hand on right long side of 4H, thumb on top of 4H and 9D FU underneath but side-jogged to left. While mentioning and touching exposed part of 9D with LH forefinger ((wear rubber glove)), do essentially the Paddle Move with two RH cards while turning them FD. See Peter Samelson's "New York Transpo" for nice details here and great routine.)
Show second transposition, first revealing 9D (card of main focus) in RH and then 4H on LH deck.
3. Finally (well, almost finally), do Fechter's "Be Honest, What Is That On Your Shoe?" or whatever. Reveal two black cards.
4. ACTUALLY finally, while surprise from Fechter fase detumesces, top-change two face-down blacks for two reds (supposed blacks) which you table. Quietly cut two blacks to middle while reversing them (insert details here yourself). Spread deck FU "to find those two red cards", while reiterating out loud (especially in a family restaurant) that these effects are called Card Switches because the two FDn cards in the middle of deck are "the 9 of D and 4 of H ... Oh NO, the two BLACK cards: ANOTHER Card Switch!"
Promise spectators that "When I find out how it all works, I'll be happy to tell you!"
Last-minute idea: make all of the phases look like the Fechter in-spectator's-hand phase!