by White Line Nightmare
I've bought a few (SWAT, Marines) for their gear, and have had some success boil & popping their limbs and heads off.
The SWAT figures would come apart with very little effort, actually.
Don't know about the brand-new stuff, as I've not tried to take it apart, but my impression from the WWII parachute figures is that BBI is using better, less rubbery plastic. Boil & popping might work (especially with the heads, hands, and boots/lower legs), but the legs and arms might be stuck in the hard plastic torso.