First a disclaimer -- I'm not a plumber and have very little experience with this. I've got a 1960's era American Standard shower with two faucets (hot & cold). Showerhead was dripping so I removed the cold water escutcheon and found the stem embedded in a thick layer of grout of some sort, seen in the picture, presumably for waterproofing. I chiseled it away with a screwdriver and hammer (lots of dust) over an hour and the final result can be seen in the next picture. I got a new shower stem that is installed and works (no more dripping!), but I don't know if I need to basically make it the way it was before in terms of sealing it. The cement/grout that was in there before went as far deep as the bonnet, and was at least an inch thick fully circumferential. -Do I need to go this deep again as it was before? -What material? Casual recommendations have included 100% silicon caulk, plumber's putty. -As big of a PITA it was, I knew I could get whatever grout it was out with a chisel. With the recommended material, how easy/hard is it to remove again if needed, and how would I remove it? -Do I just need a thin layer around the more superficial part even with the tile to protect water coming in? -Do I leave an inferior segment ~25% un-sealed to allow moisture out? -Some water got into the grout when the cartridge was being switched out. Should I be very concerned about drying this up before sealing? -If I have to seal it as deeply as before, am I protecting against leaks from within the valve? Is this necessary? Thanks very much.