Clean tiles / tiles with buttermilk
I have come to an ingenious Putzmöglichkeit ears, as you get matte tiles in the shower, the shower tray itself, matte bath etc. clean.
The product is 100% biodegradable, super cheap, easy to use - and it works!
Simply rub Buttermilk with circular motions thoroughly on the relevant places, let it act for about 1/2 hour, rinse thoroughly and then dry it.
If it does not go away the first time, repeat the whole thing.
It worked great for me.
