Cleaning bunny stains off tiles...

I've had the hutches indoors for nine years and now the rabbits live outside, I can move them... the problem is that there is nine years worth of bunny pee staining the tiles underneath. I've tried household stuff like vinegar and domestic cleaner stuff like those fizzy sprays... scrubbing pads and I think I even tried a brillo pad.

I wondered if anyone had any ideas of anything short of acid that could get calcified stains off my tiles!

Thanks.

warm vinegar!

seriously - warm citric acid works a treat (like used to be available for de-scaling sterilisers, but now you have to buy the tubs of it in the brewing section).

It might be something you have to keep working at for a while - i.e. treat top layer with vinegar, scrub off, treat next layer, scrub etc

Thanks I spent the best part of a day scrubbing away months ago but I never tried it warm, will have to have a go at that