How to clean under the sliding seal on a tumbler lid
Gunk builds up under these sliding seals, and soaking them in bleach or soap won't remove it because the tight clearance prevents any agitation. This trapped grime makes the lids seem impossible to clean, causing people to abandon their travel mugs entirely. To actually reach the mess, you have to carefully pry the seal up with a butter knife, though this risks breaking the lid or losing the small silicone piece.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
How to clean under the sliding seal on a tumbler lid
- 1Using a butter knife or similar tool to pop or pry the slider out for cleaningDid this help you?
- 2Replacing the lid entirely when it becomes too difficult to clean or breaks during removalDid this help you?
- 3Popping the sliding mechanism off the lid to clean underneathDid this help you?
- 4Soaking the lid in water with denture or retainer cleaning tabletsDid this help you?
- 5Using a Waterpik or water flosser to blast the gunk out of the crevicesDid this help you?
- 6Using an ultrasonic cleanerDid this help you?
- 7Avoiding sliding lids entirely by purchasing cups with magnetic slidersDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I recently bought an Ozark Trail 12 OZ Thermos cup had zero difficulty cleaning until a couple weeks went by and I noticed this gunk build up”source ↗
“I soaked it in bleach and dish soap for a couple days but alas that didn't do anything I obviously need something to agitate but I have no clue what the hell could get in there so here I am”source ↗
“You might’ve just saved all my Starbucks travel mugs that I can’t stand to use because they’re impossible to clean”source ↗
“I get a butter knife under there and pop it up. Careful, the little silicone circle is gonna try and get away from you.”source ↗
“I have killed one lid doing that, but many others have survived this treatment. And honestly, if you can't get it off to clean under there do you want to drink thru it anyway.”source ↗
“The seal on it slides back and forth, doesn't come out as far as I can tell, and the seal has near 0 tolerance for getting anything under it. Any ideas?”source ↗
Where this came up
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