I've never done a special trip just for CRH pickups, but then again, maybe that's just me - I don't like the idea of using up any gas or spewing out any carbon just to satisfy my itches. However we did stop at some very small banks in small towns on the our vacation through the Western states last month, and we found a few goodies along the way. (My neighbor actually suggested it before I had read about it here; he actually brought up CRH (though not by name) as something a friend had done, stopping by small banks and getting old rolls. I'm glad he's too busy to CRH himself!)
Anyhow to answer your question about banks with or without accounts: Definitely stop at the banks that you don't have an account with as well. But be sure to bring in your charm, your smile, and your friendly attitude. I've only been asked once if I had an account, and I truthfully said no (C'mon! If you lie, and they ask for your account number, what would you do?) and since she had taken the trouble to get $31 in loose halves already, she said she'd make an exception "just this once." Yeah, whatever! Maybe I'll try again there someday anyhow and see if another teller cares, or offers another one-time exception!
I'm thinking that if I were to be asked if I had an account, I might explain that I'm from out of town. (True on a road trip anyhow!) A nice excuse for not having an account, and it might start up some friendly banter in the process.
In the bank where I *do* have an account, I come up to the counter brandishing my ATM card, just to give the tellers an extra clue without having to ask that I *am* an account holder; that might give me an extra advantage over a non-account holder.
(I was on a quick trip to another city today, and it drove me crazy passing so many banks ... on a Sunday. Oh well.)