Prolly once a week.

I use a metal thermos and I go 1 week then I soak with cafiza and boiling water for a few minutes

everyday.

I can go a few months. I drink one big one a day and leave the cap off overnight until I refill it in the morning. Leaving the cap off really helps keep the mold away

Wash them???

I only get dishwasher safe coffee tumblers and I wash them daily. I have enough respiratory goo without adding mold to the mix.

Mold and bacteria can grow in it within a day or two, even if it’s not visible. I hand wash mine once every week or two. I also sanitize it regularly by pouring boiling water in the tumbler (it’s metal) when I make tea, then leaving the hot water in for about 10 minutes.

I wash the parts my mouth touches pretty regularly. The other bits, especially if the don’t get backwash? Maybe a few times a year the whole thing goes in the dishwasher. Disassembly and careful hand washing? Bitch, you’re a water bottle. You don’t get that!

If we’re talking for water drinking only? Rinse out each day. Wash every other day. If I put coffee in, full wash each day.

About 16 years and counting

I don’t deep clean mine unless its needed

I usually just rinse it out and call it a day.

Typically I rinse it out daily and bout 1/week actually scrub it with soap or put it in the dishwasher

Every couple of days I will squirt some dish soap in there with water and give it a thorough shake. Every week or so I actually disassemble it for a proper clean.

Not too long. Like once a week or every other week. What happens is I forget and leave water in it, and then I’ll wash it.

Asking because the tumbler I use has a lot of little parts, so I easily go weeks between washing. I’m hoping someone more knowledgeable than me shares a good reason why I shouldn’t do that, because I feel a bit self conscious about it, but not enough to frequently wash.