As said, just use them for whatever. They are worth a dollar (unless un-circulated, them maybe worth a little more).
I used to use dollar coins all the time on the toll roads before I got a tag.
They were easy to store and find in the vehicle, and my wife would not take them out like she did with dollar bills.
Since then, I have not used them, I had a lot of the Susan B. and Sacagawea dollars. Have not seem many of the Presidential dollar coins.
Heck, I need to go look in my cars and see what I have.
I don't like carrying coins around, so I don't care for dollar coins, although I do understand the economics of it.