Linda...I have been using the Penofin Product line of cleaners and stain for over 15 years. I recently performed a "test" set to demonstrate the way these products work.
In the attached pic are four sections of weathered cedar fence that were "processed" using Penofin's line of products. The far left is a control section left untouched. The next one to the right is what it looks like after using the oxygen based cleaner. The next one over was cleaned and then the brightener was used. The last one shows a coat of oil (Blue label) "transparent redwood" on a cleaned and brightened piece.
The Penofin cleaner is a dry powder that is mixed with water and then applied with a garden sprayer. The Brightener is also mixed and applied the same way. These boards were lightly scrubbed with a brush and rinsed with running water (garden hose). Penofin also makes a "stripper" which comes in a liquid form...this would need to be used if the existing wood still has residual finishes.
Power washing is an option but it will erode the wood fibers with a soft wood like cedar.
Earlier this week I used just the cleaner on a hardwood deck and my power washer to remove the residue (rather that scrubbing) in this case a power washer is fine as the hardwood decking is not damaged.
Thank you KMS! That is so extremely helpful. I love that I can mix it with water and use with a garden sprayer. That's my speed. I'm wasn't looking forward to the whole power washing thing ...
here is a link to Penofins web page...there are a couple of videos there.
BTW...I am one of 3 certified Penofin pros in the state of Colorado...you can DIY this or look up other pro's in your area.
KMS, thanks so much for the link!