The Loyd candles had no finger clips and were rather difficult to grip in use. Owen added two clips for the most difficult candle to grip. They also added a series of "small bumps" to another portion of the apparatus to improve grip. In addition, Owen changed the shape of the floating tank from hemispherical to cylindrical.
The best candles I've seen and handled are the Owen. Considering the work involved in making the set of four, they are bargain priced.
The Loyd version work well. It's just that, as made, they are rather difficult to hold in use. I've seen modified and even modified Loyd candles myself to improve the grip. Modifications included adding texturing and finger clips.
The Owen candles are available new from Owen Magic Supreme in Azusa. However both Owen and Loyd do show up on magic auctions.
This effect is most convincing if there is some distance between the performer and the audience.
BTW - you can see a not too bad routine with the Loyd candles on the Don Alan Magic Ranch DVD set from Todd Karr. The performer surprisingly is Sam Berland. The candles are by far the best thing he does on the DVD.