Cleaning and Stain Removal - Need advice for granite and grout sealer

In our remodel, we will have new granite in our kitchen and porcelain tile in our bathroom floors and shower area. I know that the grout will need to be sealed, but I've been reading threads where people have asked how to remove the sealer because the sealer has attracted dirt to the grout; or that the sealer didn't work well, or people forgot to reseal. I understand that there is a product that will help seal granite for 10 years or its lifetime as well as grout. Has anyone used this application and what is it? There's also water and solvent based sealers for the grout, what do you suggest?

A couple coats of penetrating grout sealer should get you started. Then, reseal periodically. Keep granite tiles sealed with recommended sealer for natural stone two or three times a year. Porcelain is very hard and dense and needs no sealer.