You did not mention the species of wood and the age of the deck.
Lets say you have a CCA deck. Lets also say you just built it.
Now, CCA when new or off the shelve is full of additives meaning its very wet. Nothing will hold on this material until its dried out. In Texas, this would take about 30 days in our July heat. After that paint/stain will hold and you will get good results.
Now as far as stain. I really Like CWF-UV from the Flood Company a sub of Sherwin Williams. I also like any, any product from the wolman Company for treating/staining decks. Both are well worth your money and will last about three years under less severe conditions.
Both of these products are not topical but do soak in only after the wood has properly dried out to soak up the stain.