In article 45229175$0$81766
,
p says...
Actually, the best item you used was the nylon scrub pad. I find these are
great for safely cleaning grout film off new tiles as well as soap scum and
other films that coat tiles.

Yup! The sugar, as usual, was a placebo. ;-) The surface of most
tile is nonporous so mortar doesn't stick very well. I've left
small globs of thiset on the surface (quite by accident) and just
flicked it off with a fingernail. A few times I also left specs of
grout and a few times didn't get all the haze off at first[*]. The
blue-green ScotchBrite pads are wonders at cleaning tile.
[*] don't do this with the epoxy grouts!

--
Keith