I think many of the suggestions on this thread are very helpful. As with the Tea Tree Oil, Borax needs to be used with caution! Especially as cats groom themselves so there's a high likelihood that they will ingest the stuff. Borax is even considered to be toxic by the EPA when ingested. Obviously diluted amounts are less toxic, but since dialysis is the only method for rescuing a cat that has too much exposure to Borax, I would highly recommend a lot of thought before resorting to Borax. The vaseline and vegetable oil are meant to smother the mites.