R.C.
Get a call from the dentist, who says nothing but water before bedtime! It's not your choice or theirs - it's just the rule.
In my opinion, the pull-ups with cool-alert are worthwhile. Otherwise, you might want to invest in a few pairs of plastic pants for over their underwear. You really can't train them at night - do what you can during the daytime, and just deal with however it works out for them at night.