The magic solvent is 'Gunwash'.. used to clean automotive paint guns, available in 5 gallon cans.. get yourself a chinese paint gun and use it to clean your parts... the constant air flow is usually enough to remove most stuff, and you can inject small amounts of solvent which will erode the goop. a 5 gallon can lasts me more than a year, and I take a lot of stuff apart! (doesn't always get put back together). It can eat some plastics, haven't found any of those on chainsaws yet, but it will demolish calculator keys and some clear plastics. this system works WONDERS on carbs, dissolves varnish quickly.
I used to use brake cleaner, but found a can wouldn't last at all, most of it wasted... this stuff is every bit as strong and goes further.