Rosin. In the old days when I was a dancer we always had a rosin box so we could rub our shoes in the and that prevents slipping Here is a link you can use it on any sort of dance shoes even those this one is supposed to be for toe shoes.
This bag is enough for shorts and tees. My friend has the bag, but she's not online right now. I don't know if it's JUST 4 compartment, it sounds like it. You're better off getting a tote bag. I use this bag And I put my school books, dance clothes, ...
You might want to check Discount Dance online.