Steve - might as well quit screwing around with it.
Go to HD and buy their utility garden sprayer for $9.99. It holds two
gallons of material.
Buy your poly (gloss is best for sealing, semi for finishing), thin by
50%, and adjust your little spray nozzle to the desired pattern.
Pump her up and let her go.
I used to seal closet shelves, backs of factory cabs that were really
rough and unsealed and anything else I needed to reduce moisture
movement or give just a bit of protection.
This pump sprayer application method always resorted in gasps of
disbelief by the unknowing, though. The key is the really thin poly,
it will shrink so much there is no sign of what sprayed it.
Since most deck finishes are applied only on one side, this method is
a great way to seal the unseen side of the wood as well and takes only
a few minutes.
As long as the top side stays open for a couple of months before
applying a finish, the moisture will migrate to the top of he deck
boards (wicking up as the exposed top dries out) and you won't have a
problems with peeling.