I just stripped a Atlas MP15 with 91% alcohol. It seemed to work better in a warmer room for some reason. It removed everything off the plastic/abs shell. Even the decals came off after some time. I soaked it for a hour and then tested with old toothbrush, if the paint did not remove easy keep soaking and scrubbing lightly. It took 2 days to remove all the paint. The alcohol will not remove paint from metal surfaces I found out.
This is my first attempt at this, so I am learning too