I would throw in the "valuable" coin along WITH the appropriate tip.
There was a younger teller at one of my dump banks a year or so ago who asked me about coins one time while I was dumping halves. I give him a quick history about silver coins and told him about the
Red Book if he was interested in collecting.
Whenever I stopped at that branch again I tried to bring with me a roll find like a
Wheat cent or
Buffalo nickel or
V nickel or
Indian Head cent to pass along in the advancement of the hobby to give to him as well as the history of that specific design / coin.
He must have transferred to a different branch or found a different career as he only worked there for 4 months or so.
Hopefully I made a positive influence on him and maybe made him a future collector.
All of the older tellers seem to know what they are looking for as I have spied steel pennies and a few nickels that they have sitting in the half and dollar spots in their trays.
If I see them I make mention of them and of course they say they are keeping them but I try to pass a little knowledge along about their finds when I can.