I bought a shed a few years ago, nipped in to ask them to ply wood the floor before delivery. As I arrived I saw they dipped each shed panel in a very watery dip in a tank/tray they had made. They dipped it straight in and out then left it to drip dry above the tray.
So if thats how they treat sheds then I would assume the fence panels and posts are done the same. (So that the wood does'nt absorb too much liquid)
Also many years ago a joiner that made some fencing for us (over 80') and soaked the posts overnight in some barrels he brought, not sure what was in the mix but I am sure some of the posts are still staning and they were done in the early 80's (fencing did'nt last due to not being retreated)
My current neighber installed fencing all round her garden just before I moved in around june 2009 and the posts are allready starting to fail, one has allready broke, admitted these are 6' tall feance posts and panels, our garden they were only 3' tall.
Preparation, take time , do the job thoroughly.