I have some really grubby looking vertical blinds in my conservatory. some have black mildew on and as the room is large, it's a lot of blinds to clean. Any ideas on how to tackle this please?
A few years ago I put a few inches of warm water into the bath, added soap powder and scrubbed them. That worked fine. I did the same with some different ones last year and they went slimy, wouldn't dry, and had to be replaced.