Not a silly question - this has happened to me more than I would like as we went through potty training. If it's just a nugget or two, I usually scoop it out and let her continue to play. Then I throw whatever toys were in with her at the time in the dishwasher and spritz the tub down with a general bathroom cleaner later that night. If it's a full on BM, I scoop her out right away, and wash the toys and scrub down the tub asap. So much fun!