Here's "Hoo" with Coins

A half dollar is clearly placed in the hand. It completely vanishes. Both hands are shown absolutely empty. The coin immediately materializes. The routining, misdirection, and psychology will allow you to fool the experts. Absolutely no tossing motions. The booklet fully describes 10 effects with a "hoo" coin, including three routines, suggested patter, and illustrations. The most complete treatise ever published on the hook coin. Edited, illustrated, and printed by Ellison Poland (author of Wonderful Routines of Magic).

Quotes from the 1974 publication release:

John Braun: "This will allow anyone to fool the experts."

J. B. Bobo: "In your excellent treatise, you have done more with this gimmicked coin than anyone I know, including Bobo! It contains such important new information on the subject that it should be in the hands of every coin worker."