Promising reviews: “Didn’t realize how gross my mouthguard was. Sorry, this is kind of gross. But man does this stuff work! I’d been brushing every night with soap and water as directed by my dentist. The pic is after one three-minute soak with this product. It does the job!” —Kelli Gonzalez
“These are absolutely wonderful in cleaning my thermos. I use these once a week, and doing so prevents my thermos from developing a weird, old coffee smell. Much cheaper than buying thermos cleaner tablets.” —Santo Esmeraldo
Get a pack of 126 from Amazon for $5.74 (or $5.45 with the Subscribe & Save option).