It depends on were you dance. If it is just in studios, than you just have to brush them to get them back up, so they are not to slippery. If you dance in public venues, you also have to deal with dirt and moisture. I brush our shoes after every dance we go to and sometimes during a dance, if they get to slippery.
If you have to deal with dirt on them, than it is good to have some less severe brushes, for getting dirt of, so they last longer.