In this document, forensic scientists extract Pseudo from various OTC products and compare the effectiveness of the various different methods (lenght in time, freezer etc.) They refer to Rhodium in the refrences.
Extraction of Over the Counter Medications
A Preliminary Study Report
By: Gene N. Gietzen of Forensic Consulting Associates.
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_imgs/pdf.gif)
Post 514223 (https://www.thevespiary.org/talk/index.php?topic=8749.msg51422300#msg51422300)
(Giver_Hell: "Interesting article about extraction techniques", Stimulants)