My stocks of citric acid have almost ended, but is oxalic and acetic acid. As you consider, whether it is possible to use it as clearing agent and in what concentration
He quotes Swain "this bath is most viguorous" and should clear in 10min if developed in Rochelle Salts and 20 to 30 min if developed in Sodium Acetate.
I have never tried this myself, just reporting what I have read. If you give it a try, report back and let us know how it works.