Tiles are always washed: above the kitchen worktop and throughout the bathroom, as part of any standard cleaning from UAH 1,950. The joints between them are a different job.
Grout is porous and absorbs moisture and grease, so wiping it with a cloth changes nothing. Cleaning the joints requires a steam cleaner: steam softens the deposit, and it is then brushed out. That is a separate option for UAH 350, and it has to be requested in advance so the cleaner brings the machine.
What to expect realistically: fresh deposits and greyness come off almost completely. Grout that has been dark for several years, or has mould inside the layer, becomes lighter but never white again — at that point it is a question of replacing the grout, not of cleaning it. We say so before starting rather than after.
Clients usually order the joints together with the shower cabin and the taps, where limescale builds up in exactly the same way.