What kind of ear plugs do you use for your DC's with tubes?

We are not happy with the ones that we are currently using. They wear out after a few uses and sometimes leave small pieces behind after I take them out. We could buy some from the ENT but they are $30 a set and I have 2 kids with tubes. I have a feeling that this route could get pretty pricey. We are currently using the plugs that are bright orange and are like a soft wax that you mold into their ears. They are like $5.00 at WalMart and I can't seem to find any other options. Any suggestions?