Ironically just today the RVer next to us started to replaced his vinyl trim. He discovered that the replacement strip that he bought was the incorrect size. Since he already had the trim off, he put it in a bucket with water and bleach. All the black spots came off and the trim is clean and pliable again. Need I tell you he just put it back on.
AWESOME stuff. It is also VERY good for removing odors. I have sprayed all the fabric areas in my fiver and it reduced the new odors dramaticly. I keep in the rv on hand all the time. PCM