were to buy griffins copper paint/chemical root pruning

i have read on forums and books that theres a paint called griffins that you can paint in pots to prune roots.This is done to keep the roots in the soil rather then going pot bound and stoping growth.It is also good for when it come's time to transplant because it keeps all the roots protected by the soil and prevents stress.You would also be able to grow bigger plants in smaller contains which shoulds good to me since i be growing in a cabinet.Does anyone know were to buy this or anything else that does the same thing?

Excess copper will also kill the micro organisms in the soil.

Copper Toxicity:
Copper is required in very small amounts and readily becomes toxic in solution culture if not carefully controlled. Excess values will induce iron deficiency. Root growth will be suppressed followed by symptoms of iron chlorosis, stunting, reduced branching, abnormal darkening and thickening of roots. (Reefermans nute guide, I believe)

SpinOut is expensive and only comes in 2.5 gallon cans. I think its over $100. Uncle Ben
over at Ganja world had a little blurb on it. but he got deleted for being disruptive.