Just yesterday I bought a Minox B (love it) and have been thinking about how to develop film at home without having to buy the Minox daylight developing tank.
For developing, I've been thinking about using a tube or pipe with a diameter large enough for the film to be suspended vertically with a weight at the bottom of the film. There would be a light-tight baffle at either end, with a stopper or valve at the bottom, so the set-up could be used like the daylight development tank. Chemistry can be poured in at the top, and drained from the bottom once that step is complete. The tube/pipe needs to be about 20 inches long or whatever, to accommodate the length of whatever number of exposures on the film. A tube/pipe with too large a diameter would be wasteful of chemistry so finding the right diameter is important. I'm thinking 1/2 or 3/4 " plumbing water pipe in copper or PCV. Agitation could be done by rotating the tube, by dispacing the tube sideways an inch or two with your hand for and back, or by touching the tube with a vibrator. (the kind used for relaxing tense muscles)
Think it could work.
Remember, you heard it here first, and if anyone goes on to patent this idea, I want a piece of the action.