I'm not sure yet how it effects the integrity of the plastic, so just a thought. I used a cleaning product called kaboom. It comes in a purple bottle. It's pretty brutal stuff. I usually would clean nasty old tubs and showers with it. That said, I tried it on a particularly messy pony who was in otherwise great condition. She had a red/pink blotch across one side. It worked! She looks like new. I only used a tiny diluted amount, less than a squirt, and didn't let it touch her hair. I've never mentioned or posted it before since I was waiting to see if it did damage I can't see yet.