Yeah, I've used it a couple times, the only thing listed is KNO3 (you know my husband is a chemist so he keeps me from doing anyrthing really dumb) But in old, or not so old fert, threads there's the DIY ferys using this, nu-salt, epsom salts etc.
I think I told you 1 big box sells another stump remover with something nasty in it. I thought your well water had a ton of nitrates? Now you're doing pressure CO2, not enough?