I am going to pressure wash a deck and going to reapply a stain and seal it.
1st question; Can stain be sprayed on?
2nd; What is the best method to do this job?
Yes, the stain can be sprayed on being certain to keep the stain stirred during application and before you poor any new stain into your sprayer. You don't want to have a multi toned deck.
Many times for decks of 400 square feet or less we use the pump up hand held garden sprayer. Careful not to puddle the stain as it will not absorb and will flake.