Hey, did you look at?
https://www.thevespiary.org/rhodium/Rhodium/chemistry/peracid.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/peracid.html)
Check out the link, it's got heaps of info regarding the procedure and work up, swim just uses the “Buffered Performic acid Oxidation” as it says, works perfectly and nice yields too.
-ApprenticeCook