I use my Scotch and Soda in an interesting way. If my method has been published somewhere, I am unaware. I do not believe that I am revealing any secrets that have been comercialized and sold by a dealer.
My presentation is so simple that I would be truly amazed if no one has ever thought about it.
SO HERE GOES.
Magi produces a balloon, which he inflates.
Then, he pulls two coins (a "rare" U.S. Kennedy half dollar, and a Mexican 20 Centavo, (souvenir from a Cancun vacation),
which he is carrying as a good luck charm.
He wraps the coin in a small piece of paper,
displaying the separate coins in a manner that there is no doubt in any specs. mind that they are wrapped in the paper.
He places the paper wrapped coins on a plate or something handy, ignites the wrapped coins, and VOILA!....... only the half is there.
He bursts the balloon, and wonderously...
there is the CENTAVO.
As far as fooling with chemicals that generate heat, BE CAREFUL.
These kinds of things are prone to mishap.
They could injure someone or damage property.
"Pick any card. NOT that one!!!"