There is a stain removal called "Zout"....IF you can find it GET IT. It is THE best stain removal product I've ever used. You can find it at Walgreens, WalMart, and some Targets in the fabric stain treatment aisles.
Aside from that, the Oxi Clean product (in powder form in tub) works very well...(follow instructions carefully), or in spray from..tho not AS effective.

Applying lotsa water with soap alone should take care of this, too. Lather, rinse with lotsa water...dab up what comes loose...repeat until it all comes out. It is a waterbased paint...so long as you delute it down, over n over...and repeating that cleaning process, it should all come out..just takes patience...and some effort. All should be fine.

Hope this helps.

Shangrala