I recall a thread or 2, and the verbiage was the effectives or more the -lack of effectiveness - of Ferrous Cleaner. I believe there was a post of 2 stating the Thioglyci has a limited shelf life...
Whaddya say. Finite shelf life. 3 years, 5 years...

Just doing a spring purge. I see a bottle or 2 of 1Z Wheel Cleaner that is either staying or getting tossed. I haven't used FC in quite some time. Since wheel coatings became a thing, even post winter cleanup of winter wheels is a breeze.