I'm going to give a variety and kind of talk to myself. I'm not sure what 'clean' in meaning is to you.
What about "Everytime We Touch" by Cascada? I choreographed an adorable pom routine to it for the spirit camp I taught. It easily adds tumbling, too.
I don't know the ages, but if they're the appropriate age, you could use 7 things or Life's What You Make It by Miley Cyrus/Hannah Montanna.
Dirty Little Secret by All-American Rejects can be cute.
Aly and AJ redid some songs including Walkin on Sunshine and Do You Believe in Magic that are really good. I love them!
If they're older, First Tme by LifeHouse would be nice or Honestly by Cartel. I say this simply because not a lot of younger kids know these groups.
Hanging on by Cheyenne Kimball is a good one.
I don't know what direction you're going in, but Sadie Hawkins Dance by Relient K has the potential to be absolutely adorable and hilarious!!!
YouTube - Sadie Hawkins Dance
Since You've Been Gone by Kelly Clarkson could work.
I'm not sure about this one because I've never seen it used, but I can see a routine forming in my head, so I'll throw it out there. Time after Time by Quiet Drive. It's pretty much the same words as the Cindy Lauper version, but with more guitars and an amped-up beat.
Up Up Up by Rose Falcon is a seldom-heard song. I believe it was in either Inspector Gadget or its sequel. The slow parts aren't super slow, but there is a definite variance in speed.
If you don't know some of these songs, you could go to Rhapsody.com. It Lets you listen to entire songs for free up to 25 times each.