We don’t have a dishwasher.
We use a small thermos, travel mug each a water bottle each pretty much daily.
DS water bottles are grim - we have 4 screw top, suck on the spout type and and a bugger to clean. I could Milton them every night (we have enough for this) the bottles gets black mould on the bottom despite my best scrubbing with a bottle brush. Difficult to get them and the tops completely dry
Travel mugs- the screw bits where the lid attached is full of brown gunk - presumable hot chocolate. The cups themselves are ok. The bit around the spout where you drink pretty grim and impossible to clean with bottle brush. Again we have enough that I could Milton them.
Thermos ok ish again lid is more of an issue
All of them are a bugger to stand up on the drying rack - when dry do people screw the lids back on ??
This is going to be my one news year resolution as it bugs me endlessly
I’ve seen various things on YouTube, use bleach , don’t use bleach, use rice on bottle (great idea but what about the lids)
We have numerous bottles as we like them for car journeys, schools, soda stream, walks etc and people give them as presents.
Mainly we have metal ones and few plastic ones.