We have been doing some deep cleaning last night on the boat interior cushions and tried several items on a couple trouble spots, as I was out of the Eraser: 409, Bleach White tire cleaner and 3M'S vinyl cleaner. None of those items worked. The Erasor took it off with no effort, plus now the vinyl is whitey white. I always follow up afterwards with a soft brush and 3Ms cleaner/conditioner to get in to the threads and grain, then go over it all with the 303 heavily a couple times and let it soak in. As a rule, I'll just use the Eraser on troublesome spots or for when doing a deep cleaning once a yr, not every day use.

the best thing I have found is that magic eraser. it can clean anything, or at least damn close to. if that does not work, spray some roll off and let that sit then blast it with the magic eraser. between those two things we clean almost everything on a 145 footer and all the tenders and toys. and we have three 10 ft dock boxes full of cleaning supplies and those two things get used the most by far, and I usually stock about 100 magic erasers and a few gallons of roll off.

Cleaning
 

Yep agree with the "Majic Eraser" I spray vynal with Marine Spray Nine let soak then rub with the majic eraser, wash off then hit vynal with a conditioner. Bleach white, and other cleaners are good on the vynal often they will eat up the threads.

Aa
 

SD-20 by Spartan Chemical - works amazingly on white vinyl. Spray it on, wait 3 seconds and then use a brush to clean and follow up by wiping it off with a clean rag or towel. Not sure if you can by it retail. I get is from an industrial distributor. Our marina uses it to detail boats. The service guy at PowerQuest Boats recommended it to me 5 years ago.

PQ26

Break out the big chemicals. If you have stain issues, use Acetone. You can get it at Home Depot. Get a rag completely wet then wipe an entire panel/cushion. Then use 303 to re-seal it. It works very well but its rough on your hands. It removes everything - if this doesnt work, forget it, you cant fix it.

grease lighting and magic eraser then apply 303. always eariser if you pull the seats. that way you can get the entire seat clean and protected.

Acetone is a last resort. It will actually melt off the outer layer of finish on the vinyl. It will also make the vinyl get dirtier easier because it removes the finish.

Yeah, I've seen the grain texture melted before from acetone use.

There was a product I used to use called Bypass (I think I'm spelling it correctly) that worked GREAT. You had to actually follow the directions and let it sit for 45 seconds to one minute, but it was an awesome product when paired with a mild or even a soft scrub brush.

It actaully sounds a lot like ROTAX454's product, but it's only about $15.00 a gallon.