I'm about to do some kitchen wall tiling using natural limestone or
suchlike. 4" squares
I made enquiries in two tile retailers regarding sealing.

The first said stick them on the wall, seal then grout, thus making cleaning
the surplus grout easier.
The second said do the sealing last so that the grout gets sealed.

Both ways therefore have their merits. I would like to hear about the
experience and preferred method of others.

Thank you

mark b