I recently discovered this one: mix baking soda and plain moisturizer (like Pond's Dry Skin Cream, or a generic formula) into a paste and use as a super mild exfoliant. Use a little or a lot for your needs. I read it Good Housekeeping while looking up product recommendations since I needed a new daily moisturizer and gentle, but inexpensive, exfoliant. Not scratchy at all, and my face felt very soft. It helped my chapped lips too.
I even shaved my armpits with the paste (instead of shaving gel). Sure, my blade was a little dull after, but it needed replacing soon anyway, and my pits were very smooth. It did a nice job of removing any deodorant gunk, dead skin, and other build up.
And I'm a HUGE fan of using olive oil for daily facial cleansing & makeup removal. My skin's much more balanced, less raw, and I get far fewer blackheads. In the summer, I mix it with castor oil, which, oddly enough, is drying.
Pumice stones for kitchen cleaning. Takes off rust spots when I've not been very nice to my cast iron. And it completely removed the wicked rust and mineral stain from the kitchen sink when we moved in. The factory smooth finish is LONG gone from the sink (I think it's original to the house - c. 1960), so I'm not too worried about scratching it, but it picks up stains so quickly and the stone is great for touch ups.
I love vinegar for removing mineral build, soap scum and stink from my veggie steamer, coffee maker, and other stuff. I soak a papertowel in vinegar, place it on the veggie steamer's heating element (unplugged of course), and let it sit over night. I usually put cling wrap over that to keep the rest of the house from smelling like vinegar. The next morning, the scale easily brushes off with a scrub pad. I've also put my razor handle in a baggy with vinegar to get rid of the soap scum and mineral deposits. For coffee makers - run the machine once with vinegar or a vinegar water mix, and then run clean water through it a few times to flush it all out.