Swish with a mixture of 1/2 cap full of warm water, a "pinch" of salt and a cap full of Listerine for 2 minutes. Repeat as needed.
I've had a bad tooth that's needed to be pulled for quite awhile now but can't afford it. I have no idea why this works, but this is the only remedy that works every time. It also works for clearing clogged sinuses.