Any question answered...

"borrowed" some of this from work, sorted it no problems.
Much better than caustic soda (from Robert Dyas) or whatever it was i'd tried before.

I was there for half an hour today scrubbing away. Bleach did something, but not much. Bought some limescale remover today so I'll try that tomorrow.

I don't even know if I'm going to have this job for that long, but the toilet and the sink were disgusting. I threw 5 mugs in the bin and salvaged 5 after a hard session of scrubbing. The guy who used to be here is a great guy but he doesn't seem to understand that type of thing.