If it were me I would take it outside, spray some 3% peroxide on the effected areas and keep the spots wet until they disappear, may take an hour or so, depending on age.
Then rinse it out with soft water and speed dry.
Or you could buy some fancy product from John Olsen that will do the same thing.
3%.....Man Now I have to get that also with my 40 vol from Sally's. I guess I have to go to my bathroom and grab some next time.
Albert-
It was 100% Cotton and I only cleaned the cushions. I used procyon with a little back-out, scrubbed then rinsed with my TM and upholstery tool. I got most of them out, buy there are two approx. 3 inches in diameter that didn't come out.
Bob why would you dilute the vinegar? It is only 5% acitic to start with. I have had good results with Bac-Out from BioKleen. Works pretty well on most types of organic staining. Does peroxide have an effect (weakening the fiber structure) on cotton fiber at that volume. Just wondering. I have also used distilled water, mist on and extract.
I usually use sodium metabisulfite (coffee remover) on water rings. If it's visible at first I might spray it real good with the sm and let dwell then continue with regular cleaning. Like Mike suggested, if it's still there after the rinse put it in the sun. I just use the sm at this stage instead of the peroxide.
I make sure to tell the custy I'll do my best but make no guarantees. Not all of them will come out.