Grooming Does his grease gland need cleaning?

[4boipigs]

Does Gimbly's grease gland need cleaning? He is a sheltie/abyssinian mix and has long fur near his rear. He doesn't have yucky fur from poop/pee, but the area of his grease grand is very sticky and the fur there is clumped together. There's also a few bits of black chunks in that area. I'm not opposed to clipping the area but I need advice if I should clean up that area while I clip him. He isn't fond of being held so doing it all at once is best.

Gimbly is the only one of my 4 pigs with this issue. I have 2 abyssinians and an American, and neither has a sticky mess like this.

 

[Guinea Pig Papa]

My boy Leo has this same issue. I have been told that the blue Dawn Ultra dish detergent does very well on this, and I have tried it on him once. It DID help somewhat, but I think it would require multiple baths to completely clean it up.