Badly stained unglazed ceramic tiles due to water absorption

[SD2017]

Hello all,
I have been a bit reckless over the years with my bathroom in the past 2-3 years and it show with the pic I have shown. I tried some products to clean these dirt stains that look deeply embedded into the tiles. I couldn't find any thread that fit this topic but is there any way to restore the tile to its original colour or am I permanently doomed. I presume it's due to the high water absorption during my showers. Anyways any help?

 

[Lithofin BOB]

I would firstly test a product to remove greases and any salts from the face with a product (we have Ceramic clean), if there is remaining staining ( coloured) I will then use a mildew remover as this can sometimes remove further organic staining to the tiles.
If staining is removed

Dry the tiles completely 4-5 days or until fully dry
After this impregnate with a specific impregnator for unglazed ceramic tiles, 1-2 saturations- leave 2-3 days to cure before use, maintain with the correct products .
Few issues here, may not be just a cleaning issue, if a salt is bound deep into this tile from edges and back you may not resolve this fully,grouting may also want complete replacement

 

[WetSaw]

Do you know if there is tanking behind the tiles? I'd be a bit concerned about the substrate getting wet.

 

[Time's Ran Out]

Brilliant reply from Bob!
Me I'd have said - it's time to renew.

 

[SD2017]

Thanks lithofin Bob and others! I will try these products and hope to god that it works! I will post a pic of the after effect if I see the improvement. But I guess the damage is structural and needs to be replaced if the mold has permanently hunkered down under the tiles right?

The colour is black so I imagine that is mold under? Correct me if I am wrong here....Don't want to over panic or anything but I thought I just want to ask the right questions so that in the future I can learn from this mistake!

 

[Time's Ran Out]

Legionnaires comes to mind!
I'd use a mask when dealing with the mould you have there. Unglazed tiles being used in an area of continuous wetting is asking for problems.

 

[JTSpas]

Hi Lithofin Bob, I liked your detailed answer. Otherwise I was thinking, if correct tiles have been used for the wet area.