A few weeks ago dh ordered some enzymes. They arrived in a bottle and consisted of a brown liquid. No smell, a bit uninspiring tbh. I want to try more eco cleaning methods and he ordered these to help. They're safe and environmentally friendly apparently.
He suggested I try them so I did. You spray the mucky area and then wait for a bit and then rinse off. You can rub them in if you want. I was a bit dubious, but tried it and it works pretty well. Even on the tiles and discoloured bath seal. You can even just spray and leave as they're none toxic or irritant.
I've been enzyming everything since then and you can even make your own out of fermented fruit peel and brown sugar. Have a look on YouTube. They're called 'garbage enzymes'.