I have not been turning all that long myself. I asked the same question when I joined here. Several people told me the Drying time is one year for each inch of thickness plus add one year to the total. A two inch thick slab would require three years drying time. However I live in the central valley in California where the humidity is bone dry and some of my woods are dry in no time. Also they put me on to left over house pain to seal the end grain. Latex has worked great for me, and clean up is just warm water and soap. The brush lives on top of the can.
Good luck with all projects.