Walnut: REMOVE SCRATCHES FROM WOOD FLOORS & FURNITURE!!! - just rub a walnut on mild to moderate scratches in wood and they disappear - just like that! See it with your own eyes in the video below.
Potato: Restore a rusted cast-iron skillet
Your beloved cast iron skillet somehow rusted, now what? The answer lies in course salt, and a potato. Potatoes contain oxalic acid, which helps to break down the rust. Pour a generous amount of salt into the skillet. Cut part of the potato off to leave a flat edge, but not so much that you can't comfortably hold it. Firmly grip the potato and scrub the bottom of the pan in a circular motion. You will see the rust start to come off, continue to scrub until the rust is gone, add more salt if necessary.
See photos and instructions on how to re-season the skillet
Lemon: Remove baked on splatter from the microwave; Clean a wood cutting board
Remove baked on microwave splatter: Cut a lemon in half and squeeze the juice into a bowl of water, then place the halves in the bowl as well. Cook it for 3-5 minutes in the microwave, depending on the wattage of your model. Allowing the water to boil, and steam the interior. Wait 5 minutes before opening the door, then wipe the inside with a clean towel. Voila!
To clean, sanitize, and remove stains from a cutting board, cut a lemon in half, cover the cutting board with salt, and use the lemon halves to work the solution into the surface until it is clean. Rinse with warm water, pat dry, and leave it out to dry completely before putting it away.
Ketchup: Clean tarnish off of brass pots
Depending on how bad the tarnish is, you can either simply rub it off by buffing the pot with a cotton rag and ketchup, or you can let the ketchup sit for 10 minutes prior to giving it a rub down for worse tarnish. If you wish, you use a equal parts salt and ketchup to scrub it clean with a soft cotton towel. Do not use synthetic fabrics though!
Sink Brush/Sponge: Quick trick to sanitize these - they're the dirtier than any toilet
The dirtiest thing in most people's houses is not in the bathroom. Your kitchen sponge and dish brush can harbor up to 200,000 times more bacteria than the toilet seat. That's disturbingly filthy. There's a simple way kill all those nasty germs! Sponges: get it wet and microwave it for 2 minutes. That will zap those microbes away! Be careful taking it out though, allow it to cool, or use tongs to remove it from the microwave - it's literally boiling hot. The dish brush: put it on the top shelf of your dishwasher the next time you start it - it will come out clean as whistle and germ free.