I know it sounds crazy, but that's the way it works. As activity on the account is reported to the credit bureaus, it goes into the files of the primary account holder (you) and the authorized user's file. That means the authorized user benefits from piggybacking onto your good credit being reported on that account. (Surprisingly, perhaps, your authorized user does not have to be aware you have done this. You could add your teenager as an authorized user without him or her knowing.)
Just keep in mind that this could backfire if your authorized user decides to go nuts and runs the balance up to or beyond the limit. Not only will you be liable for full repayment, but that negative activity will be reported to your credit file as well. Hope that helps.
The system isn't looking at the size of the purchase or the amount of time between purchase and repayment—only that a transaction is recorded and payment is received according to the terms and conditions you agreed to when you opened the account.
These days it's important for every adult to own one good, all-purpose credit card for the purpose of maintaining a high credit score. To do so doesn't require one to carry a smidgen of debt (it's NOT a debt score), nor to use the thing habitually. You could use your card to purchase two apps a year ($1.98 total, paid off immediately) and build a great credit score. I have a feeling that's exactly what you plan to do. Good for you!
Now that you've cleaned the cabinets well, I'd try a good furniture polish like Lemon Pledge. That just might do the trick! If you're still not completely happy, invest a few bucks in one of my favorite kitchen products: Johnson's Jubilee Kitchen Wax. Jubilee (a venerable product we can still find online) will clean and polish everything in your new kitchen, including the melamine cabinets, Formica countertops, and appliances. I love the stuff and I think you will, too.