Do you have to use 10 spectators? What is the maximum and minimum amount of people that can be used?
Michael

You can find the Gene Grant's item in his 1955 booklet Phantini's Lost Book of Mental Secrets.
The effect is called Remoto.
A similar idea was also published in the book The Assumption Swindle by Jack Tillar.

Based on the reviews it doesn’t seem like a winner to me

I revisited my copy of Jack Kent Tillar's Assumption Swindle, which his version of Remoto. This is not the same thing as Tetra Tete. While the concept used in Remoto is similar to one used in only a part of Tetre Tete, Ken's routine has varied methods for the different revelations.

Regards,
Adam

Seems to be a silly thing to say, considering there have been zero negative reviews from anyone who has purchased or read it.

The only negative comments were from those wildly, blindly and incorrectly speculating this to be identical to other routines. It's no more identical than when you remove a pack of cards, and an audience member makes a snap judgment, saying they've seen this one before.

Regards,
Adam

Does anyone perform this effect/method? I'm trying to integrate it into my act, but I'm having some issues with the drawings and the orientation for the different phases.