Sorry, meant to say powdered grout in my last post, not adhesive. The worktops are wooden, tiles are a cream colour, although look white in photo's. I have used BAL Manilla coloured grout which is a slightly darker colour than the tiles and was shown a close matching coloured silicone. I think if i used clear it might look a bit odd, especially as there some gaps larger then others as the worktop wasn't perfectly level.
I probably do need to leave the grout a bit longer before washing off but am very aware of leaving it too long. Just fine tuning i guess.
Possibly doing sealant tomorrow, will let you know how it looks.
On another note, i have used trim around the window sill and reveal so have then used it on the rest of the splashback. Can't really decide if it looks odd or not. If you are using trim around the window reveal is it then always the done thing to use it on the rest of the splashback? The tiles are only 1 tile high once you are in the reveal. I thought about not using trim but then thought the non glazed part of the tiles showing would look weird if none was used at all.
What do others think or do?