Ceramic Tile Stain Remover

[joec1985]

I really hope someone can help. I got a door mat advertised as being outdoors and indoors. i put it on my nice new ceramic tiles at my front door and after some rain, the mat was ruined but more worryingly it’s left a terrible stain. I tried a mop with some hot water and fairy liquid but no joy. Any ideas? Thanks in advance I found a bottle of this stuff also is it worth a shot or will I ruin the tiles ?

 

[RandomGrinch]

I think I would start with something a little less powerful, like a bathroom cream cleaner, CIF perhaps?
Trialled in an inconspicuous area first, of course!