Where I live our water is very high in dissolved minerals -- every fixture and surface will develop a white film of mineral buildup if not cleaned regularly. I also run vinegar through the coffemaker to remove the mineral buildup. Sealing your brick will make it easier to clean, but won't prevent the mineral deposits from forming.

Sand molded brick is different from conventional bricks. I wouldn't do anything to it without the advice of the brick manufacturer. Removal of excess mortar has nothing to do with efflorescence so I can think of no reason to seal the brick regardless of the climate.

I have a 3 y/o and matte paint. I'm perpetually familiar with the oiled handprints that are all over my walls. I use a barely damp microfiber cloth (half damp, half dry). Rub the damp part over the marks just once or twice, then rub with the dry part. I've found that by rubbing with the dry, and sort of feathering out the moisture, I can avoid a lot of the "swirl" marks that water can leave on the paint. That takes care of almost everything. If something is left that isn't fixed that way, I usually just touch up the paint. One of the perks of matte paint.

dcarch, "There are many many many "stainless steel" types, and they are all stain resistant, not stainless." Oh man, as a boater I can vouch for the truthfulness of that statement! I've spent hours & hours scrubbing various stains & rust from so called quality marine grade "SS". (grin) Our home's front storm/screen door is made from very heavy stainless steel/brass & powdered coated. It has to be powerwashed & scrubbed/polished every spring. (ugh) Last night after I'd suggested the Magic Eraser or Bartender, DH shouted out, "Hon, can you come look? I got the spot off the sink!!" You know guys, they'd rather do it themselves...especially when they caused the, eh, *issue*. Anyway, here's what he used. We use it to get fender marks off our boat's gelcoat. He figured if it didn't hurt Isle of Somewhere's gelcoat it wouldn't hurt the silly sink. He was right. So, I guess there's another weapon in the arsenal if anybody's else has black ugly marks on their porcelain sinks. We bought ours at West Marine but it might be available at hardware stores (but probably not...pretty sure it's a marine product). /tricia Here is a link that might be useful: 3M Boat Stuff