I've been using the lime sulfur dip on Sully on and off, pretty much since we got him in September. He had ringworm when we got him, then we treated it, and it flared up again. The dip really is very stinky. Sad to say, I've kind of gotten used to the smell though!
It is a leave-in, where you need to let it air dry and you also have to keep your furbaby from licking any of its fur during that time. If you have any questions on using it, please let me know!