Here is a project I completed last year. There was no existing finish on this house, so I used Sodium Percarbonate. If there was an existing oil-based finish, I would have used a Sodium Hydroxide to lift old finish. You can use Sodium Hydroxide as a cleaner as well, but your dilutions wouldn’t be nearly as strong as if you were using as a stripper.
I applied cleaner with a 12 volt, 20 min dwell, 40 degree rinse from 8-10". You need to get up close with mild pressure on wood to help lift dead wood fibers off. Neutralize with oxalic acid. After it dried, I stained. You will need a lift or some method of getting up close to the wood. Hard to do something like this off a ladder, and from my experience, you can’t really do it right without a proper rinse.
