So finally I have a little extra money to splurge on my girls & was looking into switching from their comfort wheels to a csw but want a little info first. I know there are two types what is the difference? What are the dimensions of the wheels? Are there any common problems with them? I was also wondering how you clean them, I've read you can get the roller blade wheel wet, but my girls poop A LOT and I'm always having to scrub them almost daily.