I just go in and ask if they have any hand wrapped coins. It really depends on the bank, most banks with coin counters will have a comparatively low stock of CWRs because
1) Few customers would roll their coin if they can just dump it in a counter
2) Business customers (the main users of rolled coin) generally loathe CWRs and so if a teller gets a large amount of CWRs they will just dump them in the counter and get rid of them
But if you let them know that you like CWRs, if they get in a large amount they might call you.