Silcone Grout Sealer
That grout should be sealed. I see no reason why it has to be silicone sealer. The newer sealers do not identify themselves as silicone, although they might be. Any good quality sealer should be fine, if in doubt call Mapei. I think their wording mentioning silicone may be old script.
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!