black grout stain on polished porcelain

[Oscarflash]

Hi I've just laid 26m2 of wood effect polished porcelain tiles (quite high end from Italy. Fioronese urban wood)
After laying them I cleaned then with ltp grimex to remove factory wax, then sealed using ltp sealer impregnator left for 20 mins then buffed them up. I left them for 24 hrs to cure then grouted in black (nightmare I know) then I washed them off then polished only to find that the grout had stained the tiles.

My question is is there a realistic way of removing these stains. My feeling is no but if anyone out there can advise I would greatly appreciate it.
I just can't see where I went wrong. I'm totally gutted.

 

[Lithofin BOB]

I would start off with a porcelain specific cement residue remover, testvonly 1-2 tiles in a descreet area. dilute 1-3 or as stated, pre wet your joints, ( you don't want to burn your black grout joints grey) flash clean 1-2 min with brush or white pad. Rinse , dry , re test a stronger dilution if req.

What make of grout is it.?

Did they advise to remove the wax first? This could have protected you

 

[Bill]

I can't see much staining from that photo. Do you have a close up?

And just for the nerds...what grout did you use?

 

[Lithofin BOB]

I timed that badly Tom !!!!! I must be a nerd

 

[Andy Allen]

Personally I would of adviced against using black grout with polished porcelain.

 

[Oscarflash]

I used mapai black grout

 

[Oscarflash]

 

[Oscarflash]

Also I noticed even pencil marks caused stains on the tiles during installation so I don't think the factory wax would of helped against this

 

[Oscarflash]

If you've successfully used a product in a similar situation could you name the brand. Thank you

 

[McLovin]

Shot in the dark but I had some cheap ceramic white tiles stain when I used Bal Ash grout. The staining was on every tile and no cleaning product could sort it. Bal Technical had no idea. I crapped my pants if I am honest as i would have had to pay for them to be replaced.

The only thing that worked an absolute treat were Flash Magic Sponges. Saved my bacon. Had to raid the local asda but they were well worth it.
I always keep a few boxes in the van just incase.