While 91% isopropyl can work as "The Spray Can Rembrandt" suggests, it can take days or soaking to get the bits of paint out of the crevices and details so I would steer clear of that method unless you want to wait a while. The other downside to 91% isopropyl is that it immediately begins to absorb moisture from the air and dilutes the concentration making less and less effective as the model sits in it.
I recommend either Easy-off oven cleaner or a citris based cleaner like from Zep. Get it in the gallon jug and after you done stripping it can be filtered and stored for future use. It has no negative effect on any of the plastics I used it on. It hasn't softened or made them brittle