Hi, Happy New Year :B
These are some things I found at various web sites:
I've only tried the bleach/vinegar and water method so far, I have the carpeted headliner also, it's been working very well on removing water stains.
#1 The people at sky harbor turned me onto a solution that works wonders. I had some roof leaks that left the rust colored stains. I used their solution and it works wonders. the solution is 1/2 bleach, 1/4 white viniger,1/4 water. put in a spray bottle and spry the area and then dab with a white cotton towel. It may take a time or two. Some of mine went away right away, a larger one took two treatments. No staining left what so ever. Just be sure to put a little plastic down over everything else so you do not bleach out what you do not want bleached out. No scrubbing needed just spray and dab.
#2Woolite Oxy Deep Spot & Stain Carpet Cleaner
#3I had water stains on my MH and E-mailed Winnebago on best way to repair it. They called and said that they used " Insta-Gone ". It worked great. Just be careful as it is a bleach and will discolor any fabric it gets on. Just do a search to find it online.
1996 31'Fleetwood Flair 30H, F53 Chassis
2005 Dodge 3500 Cummins 4X4
20' Carson Racer,CR500,CRF230,CRF230,08 Polaris Ranger
Orange County,Ca.