If you don't mind some scratches of if you work with tougher film stock the bucket method may work. Just unwind into 5 gallon buckets of developer, stop, and fix. I saw a video of someone doing it once with 16mm, looked like a total jumbled mess but was fine when they line dried it at the end.
A 5 gallon bucket is exactly what I was envisioning! A friend developed a 16mm short film (movie) in a Paterson 8-reel tank in similar fashion.