Has Anyone Heard Of This Product?

Heard of it, yes; it's use is frequently mentioned on the uncleaned discussion section on FORVM; I believe the owner of the website you've linked to is one of the prominent members there and was either the inventor or chief promoter of the various "Gringgotts" formulas. Wizard Mix #1 is designed for longer-term (a few months) room-temperature soaks and in hot water for quick treatment of bronze disease; the other formulas are designed for boiling up to loosen petrified mud and a "final solution" for stripping coins that are hopelessly corroded down to bare metal.

I can't recommend it personally since it's not a product I've used but the owner of FORVM is not only happy to allow discussion of its use to go unchallenged, but he stocks it as well; that's a good enough endorsement for me.

The owner of the site isn't the inventor of the mix but certainly promotes it and the other mixes from the same source. I haven't used it either so cannot give a personal recommendation.
Martin

Have you told BadThad yet?

Its washing soda ( carbinate/bicarbinate ) with a bit of TSC cleaner added.You can use it to boil the coins for 20 min,let cool in pot,then soak in mineral water