I let my dd paint but I control it. I only give her one color at a time, and I sit with her the whole time so if she tries to eat it I say no we don't eat paint and redirect her back to the paper. She enjoys it but only for maybe 5 minutes, so it's not something we can make an afternoon of. Once I can tell she's bored with it or starting to just be crazy, I say "okay, all done" and I take it away. I think right now she's a little young for it. Maybe in another year she'll start to actually paint "things" because right now she just slaps the paint on the paper, or goes in circles, same that she does with crayons.
I also only use the washable, non toxic paint and she does it either on the table with some paper bags taped around so she doesn't get it on the table, or sometimes even outside on the back patio so messed can just be sprayed down with the hose.