Like traditional toothpaste, kids can use Tooth Suds too. You'll still want to supervise them (kids do the darndest things after all).
Make sure they don't eat the soap or swallow the lather (which they're less likely do to than with toothpaste since there are no added sweeteners) Make sure they brush their entire mouth, including their tongue And, teach them to brush at least twice a day for two minutes each time. Also remember to replace their toothbrush approximately every three to four months, or sooner if the bristles are frayed.