I have ceramic tile that is very difficult to clean. What do you use to clean the tile. Do you scrubb with brush on hands and knees? This has been the only way so far that I can clean it. I have not sealed the tile or the grout yet.

I have a grout sealer. Can I use it to seal the tiles also?

My entire house is ceramic tile. I actually bought the Orange Glo cleaner set, and only use the mop part, and I use a tile and grout cleaner that you can buy at a home improvement store.

mariannek, there's a difference between sealing grout joints and sealing tiles, and depending on the type of tile you have installed you should use one or the other.
When you seal tile grout it protects it from moisture, mildew and stains for years, also your grout requires less cleaning because the sealing prevents dirt from entering the grout.
Glazed ceramic tiles only need to have the grout sealed. Sealing tile grout gives your tile surface greater water and mildew resistance, and is indispensable for keeping grout from getting dirty. Unsealed grout will absorb dirt, grease and grime such that it becomes impossible to clean.
For a new tile surface or re-grout, nearly all grout manufacturers advise that you wait at least 48 hours after grouting before applying sealers so the grout has time to finish setting. For maintenance of existing tilling, you should re-apply every year or two.
There are two main classifications of sealers: Membrane Forming Sealers, and Penetrating Sealers.
It's ok if you get some sealer on the tile surface providing the tile is glazed, but be sure you wipe it off before it dries, or it will be there for good. You need to remove any excess penetrating type sealer from the tile at once. It dries fairly quick, forming a haze on the tile that is about impossible to remove.
For more info search online for "how to seal grout"
Good luck!