Cleaning terracotta floor tiles

[PIGEON]

I have recently had my kitchen floor tiled with terracotta tiles. I was told that they were coated and that stains etc. wouldn't penetrate. However the tiles look grubby already (after 1 week!) and splashes of oil and balsamic vinegar show up, as do various other stains. I've mopped with my usual Flash floor cleaner, but this doesn't seem to make much difference. I don't want to damage the tiles in any way. Please advise how to treat, clean and maintain! Thank you!