I am trying to find the French for wall tile grout sealant and brands preferably stocked by MR Bric... My kitchen flat surfaces are tiles with grout and they are looking very tatty and are hell to keep clean so I am restoring them and would like to seal them when finished.
Mix 2 parts dry clean fine sand with 1 part white cement. For a kitchen mix in some epoxy resin. It is not that pure white stuff you get in packets but it looks old when it is done. Make sure it is a greyish sand, make a paste with the cement and slowly added water. When you have the consistency the packet stuff gives put in just a bit of epoxy, 10 to 12% maximum, and mix it right into the grouting.
On kitchen work surfaces it's better and in commercial kitchens necessary (UK) for very good reason so why not follow their example and use water based epoxy grout? Mapei Kerapoxy is available in some brico's. You'll have to work a bit quicker but it's a lot easier being water based to use than the old epoxy grout which was like Araldite!
Mapei also do a water resistant grout in various colours that you can also get their silicon in so it all matches up.
If you still insist on old grout then the HG range do several sealers.