Try the alcohol trick. If that doesn't work, try Tide (the laundry detergent) with Bleach alternative. Put a dab on and let it sit for maybe an hour (not in direct sunlight). Then rinse it off. That should work. If not, one last trick if it is white vinyl is to mix a paste of table salt and the juice from a fresh lemon (mix until you get a slightly runny paste like soft yogurt). Put the paste on the stain and let it sit in the sun until it dires (best to leave it on for a couple of hours). DO NOT RUB as that will be abrasive. Just dab it on and leave it. After a couple of hours, carefully rinse it off - DON'T WIPE as that will scratch as well. This trick should work well.