Cleaning with ketchup? Yup. Not your white dress shirts, of course. But ketchup will make easy work out of cleaning up around the kitchen.
8 Unexpected Ways to Clean with Ketchup

At home, we often rely on the cleaning powers of acid—both acidic, white vinegar and grapefruit make great natural additions to your clean-up kit. So it’s no surprise that ketchup—packed with citric acid and vinegar—can help you clean, too. Find out how this condiment can do your home wonders.
Psst! Before going all-out with your ketchup cleaner, we recommend testing out a small discreet spot on your item first.

Copper
Copper reacts to air by developing a layer of copper oxide, which causes it to look tarnished. Copper oxide dissolves in a mixture of weak acid and table salt, both of which are found in ketchup. Slather the ketchup onto your copper-bottomed pots and leave it on for as long as you can. Then wipe and rinse. (By the way, you get the same result with lemon juice plus salt. Check out these other things you can clean with lemon.)

Stainless steel
Stainless steel develops the same sort of tarnish as copper, it can be cleaned just as easily with ketchup. Simply slather it on, let it sit (for as long as you can), wipe, and rinse.
Cream of tartar is a useful kitchen cleaner, too! But what exactly is cream of tartar?

Cast iron
Hard as you might try to avoid it, sometimes your cast iron skillets develop rust-spots. But don’t despair—simply cover the rust spots with ketchup, let sit, then wipe clean.

Brass
Brass doorknobs and candlesticks can get to look dull, but ketchup can help. Slather it on (or soak a paper towel in ketchup and apply the paper towel to the brass object), let it sit for at least 40 minutes, then wipe and rinse.

Silver
Silver also develops tarnish, which can be cut with ketchup (slather, soak, wipe, then rinse—sensing a pattern?). If your silver has a lot of detailing, use a toothbrush to scrub the ketchup into the grooves. Rinse immediately after scrubbing.
Not sure you want to subject your grandma’s silverware to this new trick? Here’s a tried-and-true way to clean silver.

Stuck-on food
We’ve all left a dish in the oven too long, leaving us with a burnt, stuck-on mess. To get rid of those burned bits, douse the surface with ketchup, let it sit overnight and then rinse.

Garden tools
Did your pruning sheers get rusty over the winter? Squirt on some ketchup and let it sit overnight. In the morning, wipe or rinse with a hose, and your blade will be like new.

Cars
After you wash your car, use ketchup on a soft cloth instead of wax to give your finish a beautiful luster.