I don't know if you have a TD bank in your area, but I opened an account with them just for coin searching. I randomly met a branch manager at a friend's party and told him how much it sucks when tellers have attitudes about it. He told me to come to his bank and it would be an issue. I go in and I dump my bucket o'change into the coin counter (which is free) then bring my slip up to the teller and one of the tellers always says "More coins or do you feel frisky today and want to search bills?" while laughing. I tell him how I never feel frisky!
At the other banks I've used I never had much of problem, you just need to have the right attitude. I usually say if it's an issue I'll take bills, if it's cool with you I'll take more coins. I find that once they see you a few times they get interested. When they find out I'm not looking for jsut silver they get really intrigued and ask how the previous search went.