I am aware bleach does not penetrate porous things like wood. The water penetrates, but the cleaning part does not. However, can it reach?

I would say that because the bleach is dissolved in the water - if the water is absorbed into the wood - then the bleach would be absorbed in exactly the same way to the same depth
What makes you think that only the water is absorbed and the bleach does not penetrate....Show more

Depending how porous the wood is, yes. Bleach is chlorine dissolved in a solution of sodium hydroxide. If the "water" gets into the wood, the chlorine will also....Show more