Please forgive us, we would like to answer every letter we get, but there are so many we simply can't get to every single one. We do read every letter and try to select a correspondence which represents similar questions written by several readers. We want our answers to benefit as many folks as possible. Also, during our business week we must attend to being home improvement contractors which usually precludes us from taking calls.

Your persistence is as commendable as your question is frequently asked. There is no one silicone sealer that we know of that we can recommend for sealing both grout and tile, so we can't guarantee that Aqua Mix will work in your case. Where some sealers will work well to prevent water penetration in grout they may not be effective when applied to adjacent tile.

Aqua Mix makes a good product. It certainly can't hurt, and may be the correct blend for your tile-grout problem.

You might also want to contact the folks at CeramaSeal Stone and Tile Care Products, P.O. Box 33322, Seattle, WA 98133. Their free technical assistance hot line is 1 (800) 356-4903.

Glaze 'N Seal Acrylic Grout Sealer made by the Glessner Corporation in San Francisco is a product we have also used that works very well on grout.

A silicone sealer should not be applied to stop leaks in cracks. The grout should first be repaired. The surface should be very clean. A thorough scrubbing with vinegar, lemon juice or bleach should be do the trick. Surface grease (visible or not) will neutralize the effect of a silicone treatment.