Creosote reducing powder

I can't say it's useless, inside my boiler anyway. It does turn the hardened deposits into a white soft ash. Don't know about the chimney. The water jacket extracts so much of the fire's heat that my stack temperature is usually around 200, except when I add fresh wood and then it shoots up temporarily to 700-800.

My stack is usually around 125* without the draft blower running. Maybe its heat that makes it work better? If so, it is probably much more effective in a stove than a boiler.