I went in the late 60s when I was in college in North Alabama. Good tour, I would recommend you going. It is in a dry county, but I am pretty sure we were getting some tasting in. I seem to remember that they could pour you a shot, but not sell you any to leave with. Long time though, and consumption since then could have screwed up my memory.
I visited a couple of times in the early 90's. Great tour, but no samples back then and there were no sales either. But things do change, so maybe to increase sales tax revenue you can buy JD at the gift shop.
George Dickel distillery is nearby also, but it is not as entertaining as the JD facility.