Used one of these?

[nick.v.g]

have seen epoxy grouters use the gun when doing floors in prison cells I had tiled with 15/15 floor tiles. they would fill up the gaps then scrape up the excess with a putty knife, then a quick scrub with a scouring pad then sponge. the two of them would do 60 to 80 sq meters a day which is impressive and a hell of a lot faster than with a grout flout . conventional grouts I would use a float and be able to do double the area alone

 

[White Room]

Mines in cold storage