In the old days prior to 1990 or so, when grouts were
not polymer modified yet, we would mix liquid polymer
admixes into the grout as a substitute for water. This
would make the grout more stain resistant and make
the color more consistent, but it doesn't truly seal it.

Possibly his contractor mixed polymer modified powder
with additional liquid admix, which is wrong and shouldn't
be done.
Don't give in to some kind of experiment. A bad
grout job will ruin everything.

The conventional way is to just use ordinary polymer
modified grout (as all grouts come these days)
mix it with clean water, and seal it with good sealer
after 3 days of curing.

thetiler

wrote:
Hello all,

Has anyone heard of this? My brother in law just had his kitchen
remodeled and the contractor that installed the porcelain tile floor
actually mixed the sealer into the grout then applied the grout. I'm
going to be grouting my kitchen floor this weekend and just wanted to
pick some brains first!

Thanks