For Tomme, I let it grow mold and dry brush every now and then. For the other cheese that I don't want too much mold on, I wash with salted whey or oil or put herbs, spices or honey on it.
If I want pristine and clean rind on my cheese, I put honey (I use raw honey). Most important thing before all this treatment is too dry the cheese properly, I dry in cave that I set to 14-15C with humidity of around 65-75%.