It's Strange. On the one hand you want to go for less plastic by not buying plastic staws but investing in stainless steel straws. On the other hand you have to clean them and as the modern dish washers lack basket that allows the straws to be vertical so water will go through them while in the dish washer.
So what to do? Print a “plastic” holder so you can put the stainless steel straws into the dish washer. …. what a modern world.
Use PETG because of the needed temperature ranged needed in the dish washer.
The author hasn't provided the model origin yet.