If you have burnt on food and are using a non-stick but can't get the burnt food unstuck, you may as well throw that skillet away. Just warm up the skillet a little then wipe it out. The other one about the turpentine and salt to scrub the tub, I wouldn't even attempt since you have to open a window. I hit the tub with hot water and use a spray foam cleaner for bathtubs, let it sit for couple minutes then wipe the tub. It gets the rust. Rust will come off with any scrubber. It does for me.