Complete uninstall of Rhino 6 Win

I want to completely uninstall R6 so that I can approach installing my latest plugin, as if the computer was brand new and R6 had never been installed on it.

I tried uninstalling/reinstalling R6, but there is evidence of my plugins, menus, and toolbars.

I then tried
sweeping the registry for all mentions of my plugins
deleting install folders for my plugins, including AppData
reinstalling R6

and the plugins are STILL THERE.

I then:
swept the c:\ drive and deleted ALL Rhino folders
swept the c:\drive and deleted all folder-related folders
swept the registry and deleted all references to Rhino (4,5, & 6)
Reinstalled R6

and the plugins and toolbar are STILL THERE!!!

Is there an easier way for me to save what little hair I still have?