I've just asked a mate who is a tiling wad\Guru of mine. His reply was as follows
"Depends really mate. Epoxy grout should be used in food areas, but its
not 100% necessary. What type of tiles are they? Like, what are they
made of? Very important before you go ahead and grout!
My advice is go on trade tiler dot com, and buy a decent rubber
bottomed grout float with a handle (£6?) And a tilers sponge (£2?)Then
go to a proper tile shop (not B&Q or Wykes) and ask for some powdered
grout that you mix yourself. BAL or BISCEM or ARDEX are best and will
last for 30 years. Stuff from wykes like the ready mixed unibond stuff
will last a year at best and is sometimes more expensive.
Use the rubber float to push the grout into the tile joints, then turn
it 45degrees and scrape the excess off. Then use a sponge and water
and 1st wipe the tiles, change the water, then go back over it and
smooth/finish the joints.
Leave for an hour once happy, and then clean again with clean water.
Wait a further hour and then buff it with a DRY cloth."
Probably not much help to you. but Thought i'd post it anywho.