Vinyl self stick tile grout
Your store may be different, but I've never seen anyone I'd consider a "flooring guy" at those stores. Maybe a guy that works in the flooring department.
As bud said, we need specifics. Can't help without knowing what you used on what.
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!