I put the figs in a ziplock bag, spray like crazy (till they're in a pool of liquid)
After soaking a couple days, I use an old toothbrush and soapy water.
The plastic looks as good as new.
I gave it a try but the acrylic paint just won't come down.
There were some U.S. products mentioned here like pine-sol but they are not available where I live, and I wouldn't want to buy brake fluid just for this purpose.