I use Ross paste, and I've never gotten any lumps. Is it the same sort of
stiff? I mix it in a one gallon screw top kitty litter jar, the kind with a
handle and a wide mouth lid. Starting with a half gallon of water, I drop
the whole package in and shake for a while. Kids help. Then add water to the
top, and shake again. No lumps. Ready to use in about 15 minutes, although
it has a smoother consistency after a day.