Allow the homemade play dough to dry completely before you try to remove it. This makes removal much easier.
Scrape the dried play dough with a stiff brush or other hard, flat object, like a credit card. Pick up and discard the chunks of dried play dough.
Dab rubbing alcohol on the play dough. Scrub the carpet with a towel. Move the towel in one direction to avoid spreading the play dough stain around the carpet.
Squirt dish soap into a cup of cold water, if the rubbing alcohol does not remove all the play dough. Blot the play dough with a soapy towel to loosen and remove.
Vacuum the carpet after you remove the play dough, if small particles remain.