hey, eating soap can do quite a few NASTY things to you. 1, it can eat away the lining on your tongue making it painful to taste anything. 2, it can eat away the lining of your esophagus. 3. it can eat away the lining of your stomach.
wiht that said, if you're gonna wash a kid's mouth out with soap, use ivory. Pure ingredients and nothing too nasty.
and yes, if you ever want to get a restaurant in a LOT of trouble, turn off hte final rinse of the dishwasher, leave a fine film of soap, and watch the festivities. Seriously, most people won't be able to finish dinner before they need a trip to the restroom...for an hour...