Ok, teen daughter had written on her walls, with friends...no problem we knew we were decorating. Got some anti-graffitti pen 'cos some of the stuff "bled" through ordinary paint. DD painted it all herself then decided to clean the roller and tray in the bath! We now have what looks like chewing gum all over the bottom of the bath, going yuk! Any ideas? Have tried cillitbang, lighter fluid and tough cleaning stuff. It will chip off with a shoe horn (don't ask) but it's soul destroying and takes an hour to do a tiny bit. I have visitors next week and my bath looks grotty.