If nobody comes up with anything else I'll try to hunt down the post and see what @donkeypong had to say about it. Pretty sure it's the same idea as the tomato paste that we already used on him, but maybe ketchup works better.

Really hope someone has something that works as we had to shave the dog once because we hadn't kept up on his brushing and he really looked silly for a few weeks. Luckily the hair grows back so it's not the end of the world.