I've been using nasty, nasty, caustic paint strippers for years (on metal) and have never bothered trying to strip plastic. A few days ago I tried a brand of stripper and realized it wasn't water cleanup when I tried washing them off during the scrubbing process. I was left with a disgusting syrupy mess, so I threw them into a jar of Simple Green that I happened to have.
After a few days, I scrubbed them off with a toothbrush under running water, and got the cleanest results I've ever seen. So I tried just Simple Green on the next batch, including plastics... I'm mad at myself for not trying it sooner.