I just tossed out that Photoflo idea because I saw it on the Jobo site. I, and apparently no one else, have ever seemed to have actually seen this problem in real life. It kind of sidetracked the discussion from Cheryl's real problem.
Kodak made a system cleaner for commercial labs. Nasty Yellow stuff but it worked good. There are probably others and maybe even household solutions. Since you can't get to it to scrub it, I suppose that you will need to soak and rinse the lid, maybe repeatedly.
One nice thing about the Jobo lids that I use is that you can disassemble the light trap and reach every bit of it.
Good Luck and if you find something that works, be sure to let us know.