Hi CamCam, yes, it is possible to use JUST acrylic paint. My latest custom painted pleo is Just Acrylic paints. I got my last paints I used at Michaels, and you can get them at most art or hobby stores. They do vary in price from cheap, say $3.99 up to better paints and colors to $17.99 a tube. I used intermediate costs and mix different brands. I look for special colors and like the more butter consistancy paints.
Getting them off is easier if fresh, within 24 hrs, but even older can be done . The one I just did had paint that was several months old and just took lots and lots of elbow grease, soft cloths, warm water and liquid dish soap. I tend to be gentle with Pleo skin and taking my time to remove the paint is more important. Take a look at the post of painted Ugobe pleos that several members besides myself have done, including, Kat, Crewella and IMR. There is a good example of different paints used and technique with each of us,. Have fun and don't be afraid.

RWM