I just cleaned a sticky carb on a 1.50 two-stroke. I used denatured alcohol, and a five minute soak made a huge difference on a well-gummed carb. I've soaked entire engines overnight in glow fuel or alcohol, and that is a slower but gentler alternative to heat.

I did find after the soaking (which I resumed for another hour just to be sure) that the carb needed to be disassembled and scrubbed clean internally (i.e. the barrel/rotary valve) before it operated smoothly. I don't know where all the crud came from, but it really liked a good scrubbing with an epoxy brush.

Denatured alcohol has no castor in it to start another gumming cycle. When it's clean and smooth I wipe dry, then blow dry, then drop in a little synthetic oil on the moving parts.