We own a house that was built in 1958 and we have two bathrooms that are mostly tile. They're those typical 50s bathrooms that people love to hate - done in colors no one would pick now. One is yellow and blue, the other is green and blue.

I sort of like the quirky colors, and for the most part the tile looks like it's in great shape. I just want to clean them up and make sure that we maintain the tile/grout so that it can last more years.

The tile on the walls and in the tub looks in good shape - the tiles are shiny and the grout isn't worn or damaged.

The floor (in the bathroom that gets used most) doesn't look as good. The tiles aren't shiny. They look a little dingy. The grout looks low. Or almost like there's no grout.

I found some info on re-grouting. I think we can handle that. Although, removing what grout is in the tiny spaces with an exacto blade doesn't sound easy.

What I'm more wondering is how we should clean the surface of the tile. And once it is clean, should we do something to seal the surface of the tile.

My in-laws told me that they cleaned and then re-sealed their old penny tile floors.... but I'm not sure that makes sense - is sealant on kiln fired tile make sense? Or maybe it does because the old glaze is worn/scratched?

Advise me please!