when to de-fuz the wood

 I used a pressure washer. no cleaner or brightener. My fence has a five o clock shadow. I want to put on a clear waterproof sealer. Can I wet the fence and go right for the brightener since I have already washed the fence or should start I start over with the cleaner and brightener. When and how does the de-fuzzing part work? I read that the brightener opens the wood pores but the sanding closes them. so do i clean, brighten, dry, sand, brighten again the add the sealer? Please help me to understand when and how to do each step.