There are many individuals who don't see any 'potentials' in a bucket of coins. They are just a pain in the butt, and they'd gladly pay 10% surcharge to have a fist full of bills instead of rolling the coins. (I don't believe a bank will take unrolled coins of that volume, correct?) I am not one of those people. Anyways, my point is: IF the machines can be privately owned, the owner could be searching the contents. So, I would make the assumption that collectors would already be the primary owners of those machines and not just somebody who knows nothing about coins. I thought you all would be telling me: yeah, I own some Coinstar machines...
My best advice would be to take your time, once you put it into circulation it will be too late to check for some variety that you did not know about. Do a thorough job, and you wont be saying, doh wide am? I went through a thousand cents of that year. it takes time to first sort and seperate the wheaties from the chaff.
Well, here's a link to Coinstar's homepage if you want to research this a little more: http://www.coinstar.com/us/webdocs/A1-0-1 Most banks in my area offer this service for free, I'm not sure why anyone would pay close to 10% to have their change counted. And if you get to know a teller or two you might get lucky when they empty the machine... most of the "good" stuff ends up in the reject bin. My experience with "buckets" of change is... well, I'm batting zero.
I actually run and maintain a privately owned, but used by the public, coin counter. it is like a coinstar in its function but much larger. it is the model used by the feds and can process up to 10,000 coins a minute. very few valuable, odd or foreign coins make it into the machine. it has many safeguards against anything but an actual true american coin. it rejects silver, steel, foreign, bent, dirty and anything else you can imagine. 50% of customers dump the rejected coin back into there can, pocket, piggy bank. the other 50% leave it behind for me . thanks all.
You can also find coin books at the library. In a pocket full of change, I would look for any silver coins (dimes, quarters, halfs, dollars). The wheat cents are probably only worth a couple of cents unless you find something prior to 1940. You may get really lucky and find a 1931S, 1914D, 1909S, or 1909S VDB. You may find some varieties in the pocket change but you'll need the book to ferret that one out.
My own personal experiences with this type of cherry picking is to have the coins sepatated by denomination if you are going to search for die varieties and errors. Getting yourself to concentrate on one series at a time will ensure you don't miss any by accident. I've even taken all of the 1970-S cents and set them all aside for later examination. This may not work for everyone, but it may be worth trying!