I dont know what the doggy people do these days but years ago they used to cheat and brush in chalk powder!! I think the judges got wise to it in the end when it came off onto their clothes!!!

 

I'm very surprised you are finding this a problem to be honest - normally it's the additives and cereals etc in commercial food that produce unsightly stains around the mouth and eyes - raw food normally helps, or eliminates, the problem since obviously it's all natural.

My six dogs, although not show dogs, are all raw fed and I haven't ever had any issues with fur discolouration - infact my Westie (9 yrs old, raw fed whole life) is one of the whitest ones I've ever seen! - no staining, darkening or discolouration around his mouth/chin at all, and I don't clean it.

 

Can't help as I agree with SixStar, my white dog has lost his yellow tint since being on raw.

 

I don't know why it is, he must have some kind of knack to get it just under his chin.
Sorry I posted this in shows, i didn't see you had a grooming section till later