They will circulate in areas where you have one or more of the
following:
* Transit system that has a fare machine that gives dollar coins in
change for large bills.
* USPS vending machines that give dollar coins as change for large
bills.
* People who go to their bank and insist that they order dollar coins
for them. Then they get the dollar coins and they spend them.
* University and business parking lots/garages that use dollar coins as
change for large bills from machines. (Then the universities or
businesses might get a bunch cycled through their food and drink
vending machines).
* Areas with self service car washes or laundromats where they have a
change machine to break $20 into dollar coins for use in the machines.

For instance, in Los Angeles we have all of the above, and there are
some dollar coins circulating. Some= some number of millions. Very tiny
compared to the rag dollars being used, but they still circulate.