Before you use oxalic acid (wood bleach) to remove rust, please READ the warnings on the container first.
Sounds obvious, but many people (like me) do not read the warnings on their cell phones, coffee makers - or their OA containers.
-So I had the idea that some Chlorine bleach could extend the usable life of my OA solution.
BAD idea! - the stuff instantly boils up huge volumes of toxic gas.
(Fortunately, it was just a small bucket, so I just stepped outside with it - but if someone did this when soaking a whole frame, it literally could be lethal. )