I've a friend I need to put up for a while, and he creates tasks I never had before. This one I have just noticed, is brown staining running down the underside of the bathroom basin. Slightly raised, and investigation reveals it has set hard. I think it will respond to the sort of cleaner which has mild abrasive in it after a trial run. It doesn't to Dettol big strong wipes. I suspect it has something to do with hair dye. But I'm going to have to take a chair in and sit facing it and scrub with a sponge and cleaner and it will take ages. The lip of the basin is perfectly clean, so I suppose he wipes that. Find Marigolds. It's not a job for Sunday, but it needs doing. Grr.