I've been contemplating this problem for some time while I work in my printmaking studio. I thought I would tell you about a couple of things that I use as a printmaker. Recently I've learned to clean more safely. I use vegetable oil and simplegreen on oil based inkseven on Plexiglas monoprint plates. On acrylic paint I use boiling hot water and if I am trying to avoid scratching a rubber kitchen scrapper. I think Tupperware and a couple other complanies have them. the water and heat softens the pain and the hard rubber scraper gives both the angle and pressure necessary to get under the acrylic paint. You may have to give the water a couple seconds and wear gloves but those are smart things anyway.

Best of luck,

Samira