Feline Acne?

I was curious if anyone on my flist who own cats have ever had any issues with feline acne? Sam seems to have it, I noticed some crusty black things on his chin a little while back and they went away for a bit only to return sporadically. Last night, I noticed his nose was sore and red and there were the sort black black blackhead things he'd get on his chin.

It doesn't seem like it's very severe and I've been reading up on it, but I can't seem to find a good way to combat it. Some sites say to use a gentle soap, some say to use peroxide. I'd really like something a bit more all natural, really. We have plastic water bowls at the moment, so I know that could be part of the problem.