wash your mouth out

when Rigby gets older and we tell her to go wash her mouth out with soap i don't think it is going to be very effective. she is constantly eating the bubbles now. in the bathtub she is drinking the water and eating the bubbles although i strictly tell her not too. during hand washing time she will play and get a good lather and lots of bubbles then LICK her hand. she does not flinch or even make a face. gross!!!