They specifically make very special pipe cleaner-like cleaning instruments for these things. Often, the bottle may even come with it. Very handy
Edit: this is the one I have
Although I only ever drink water out of it, I do make sure to wash up the straw at least once a week.
Thing is, that the straw plugs into a gasket on the bottom of the lid and is at least partly silicon all the way through to the spout. I make sure to run the cleaner brush thing through that very regularly as well. Sometimes several times a week just to make sure it’s always clean.
I own a metal one which I assume was dishwasher safe but somehow water got trapped inside the 'extra' parts of it which could be unsanitary due to the water eventually stagnating.
Another is that the heat from the dishwasher can warp and silicone or plastic parts which will render them unusable eventually.
Not saying you're wrong but this is what I consider from the warning they provide.
I've seen a lot of fabrics that say "Dry Clean Only" because the manufacturer was too lazy, but my experience with dishes finds that the labels are generally quite accurate. Putting a non-dishwasher-safe item in usually ruins it.
Well yeah “Dishwasher safe” is an endorsement. The lack of an endorsement is not an endorsement to the contrary. Something is only “dishwasher unsafe” if it says “Hand wash only”
Seems you should also know that dishwashers only work so well as the detergent and water can access the objects inside. They are not a magic device that clean everything without fail.