The part about the freezer door seal being junk is what got me, because I always figured a fridge either works or it doesn't. For years I was the guy telling people to buy meat in bulk and freeze it flat, since that's what everyone says saves money. Then my own garage freezer started doing the same thing, meat would come out gray and spongy even though the fridge side felt cold and the ice maker was fine. I finally put a cheap thermometer in there and the temp was swinging between 5 and 25 degrees every time the door opened, so the food was basically thawing and refreezing on its own. Now I keep a thermometer in both freezers and check it once a week, it's the only way to know what's really going on in there. Stocking up on chicken still makes sense if your freezer holds below zero, but with a bad seal you're just paying to throw food away.

Ran into the same thing on a 1950s ranch house last month, 6 inch clay tile with at least three years of junk caked on it. Grabbed my 4 inch poly like always and it just slid around in there doing nothing, that loose feeling you described was my first clue too. Stuck a flashlight up after two passes and saw the glaze still shiny as glass, so I switched to a 6 inch poly first before going wire, and even that took a few passes to really bite into it. Now I keep 5, 6, and 7 inch brushes on the truck and match the flue before I even pull the rods out, saves me the guessing game. Wire works but be careful on older clay, I cracked a tile once going too hard and that turned into a whole other mess. The forums love that one size fits all line because it sells starter kits, not because it works.