You start off with a certain amount. It's a powder but it tastes like beef (or liver, I forgot). Once the hair starts growing in and it's white you can do it every other day. Eventually you can just stop it. I have a pin brush that I found in the cat aisle at my supermarket (random!) but the pins are not metal, they are coated plastic. It's great because my other pin brush would scratch so I had stopped using it. I also bought one of those undercoat brushes at PetSmart to get rid of the dead hair. I agree with TPF'er above about tying the hair. If my dog's hair is loose it irritates his eyes. I also use a baby toothbrush to wipe the area because his tears don't drain well and they get smelly.