Vinnie,Feline Acne..
 

I've had cats before who had Feline Acne,so I am 100% sure that's what Vinnie has under his Chin.
Now,he turns in to a wild cat at the vet,vet has to put a muzzle on him and wear big gloves,just to have a chance to examine him.
Also once we get back home,it takes a couple of hours before he becomes his normal self.
That is why I am asking you,if there is something I can use on his chin without a vet-visit,I'll probably call the vet and see if he can give me something without seeing Vinnie.
However if someone knows a home-remedy I'd really appreciate it.

I used a medicated acne wash on Nigel when he had chin acne, I don't remember what kind it was though.