Play standup.
For real though, the crease paint is water soluble, and biodegradeable, if they are painting with the correct paint.
As mentioned wipe it while it's still wet, and residual should come off with denatured alcohol. Just make sure you rinse that too, afterwards. I've never had ill effects on any colored jenpro, but never say never. (I don't have any China materials, sooo..)
Fast Orange actually works pretty well, too. (Even comes with a little scrubby pad attached to some bottles)
Good luck!