Sorry if I am abrupt, but I cannot stand Behr products and the sloppy job and coverage that product does. Please I hope that you have not already used this, take it back and get your money back immediately.
I build decks for a living and stain my work also. I have used inferior products as Behr, and Thompsons, both are a waste of money and time.
I would strongly suggest in using the following: CWF-UV deck stain and sealant by the Flood Company, Wolman Company has excellent deck and sealant products but they are hard to locate. Sherwin Williams has a very good product in their stores for the maintance of decks. I forget the name.
Secondly, do not buy those marketed deck cleaners. all they are is water and bleach. Clean your own deck with the following procedure.
Get a heavy duty straw push broom. Wet the deck down and pour scouring powder all over the deck. Scrub the deck in the direction of the grain and this will remove the grime and dirt. Wash the stuff off, then get a bucket of bleach and water, very little water and then bleach the deck, this will kill any fungus and mildew. Let the deck dry and when its dry notice how clean and tidy the deck is.
Now, when dry, apply your deck stain. remember, the best stuff is applied by a roller or brush. those deck sprayer things are no good.
The first time you do this, the deck will soak up the stain and chemicals, so put it on heavy. then the next spring or spring afterwards, it will not be that much of a workout.
These stated products will penetrate into the wood and give you a deep stain color, not a topical treatment like behr and thompsons.