Excess dried grout on tile lines

[Old Mod]

It's been 5 days as I've had other house jobs to get on with but I need to sort this now i have more time

Plus it's sticking out like a sore thumb

Yeah that's a bit of a mistake.
It should never have been left. The longer you leave it the more it will cure and the more likelihood it'll have to be mechanically removed.

 

[WetSaw]

Deterdek does not fundamentally effect grout

I'd be surprised if any acidic cleaner used incorrectly wouldn't "bleach" the colour from grout but I haven't used that particular Fila product so I bow to your superior knowledge

 

[Old Mod]

I'd be surprised if any acidic cleaner used incorrectly wouldn't "bleach" the colour from grout but I haven't used that particular Fila product so I bow to your superior knowledge

It's just what it says on the bottle Paul, haha
But I have used it and it is a good product, but for this application, I feel it may be multitools at dawn! Haha

 

[Battleroc]

Do you think the nylon drill bit brushes might be a good choice to try?

 

[WetSaw]

I'd try the cleaner first with a scourer. If that doesn't work try the mechanical removal option but don't use a spinning brush with acid!!