Some "blotching" with a bleach treatment can occur if not rinsed well and "air dried" before apply final oil finish.

Oxalic Acid and Peroxides are also employed this way. OA being perhaps the most common. Some folks in the log industry swear by and never using any but "Wood ReNew."

Bleach, and many of these products can have a deleterious effect on the environment and are considered dangerous. Some states do have strict rules for their use and/or application, especially near "water shed." Just an FYI, but if you flood the area with more fresh water in most instances I think you would be just fine. I would check (anonymously perhaps??) with your local DNR just to see how "strict" they are and what the fines can be...??

I would note that for most timber frames (and green woodworking in general) There is no need to have them "dried in" before applying a tradtional finish. Actually slowing the process of drying and "waxing" joints is an old and proven practice by many timber framing cultures. Most (like barns) just went natural bare wood. The patina you get in really old timber frames barns or homes can be achieve any other way than to put a fresh frame up and get it under cover as fast as possible then let slowly age and oxides. That is where that "off brown" color develops, which is different than graying. Many conifer species (the most common timber framing material globally) have now been aging for centuries in some regions and only get darker with time and oxidation. Oil finishes are the only thing to arrest this, and if exterior exposed to UV then a UV inhibitor is recommended.

Good Luck,