actually for dip coating a small object, gluing a dowel to it and putting it in a full sized drill press might do the business. I mean it won't be perfect but you can retract the quill rather slow without building anything, and it has a adjustable table. If you had a very slow power feed on the drill press that might be close to ideal?
Maybe putting a wall clock against the handle to follow the second hand would work. Or a projection of a clock or something, like tie a laser pointer to the handle so it aims at a wall clock and rotate the handle so the laser follows the seconds.
Or maybe there is no upper limit and 1 minute per 6 inches is just a reasonably fast number, so go as slow as possible.
I tried with pliers and plasti dip and transformers + varnish and usually it came out like total garbage, with transformers I don't care too much though, I just textured it a little with a towel. I associate the process with mega bad smells, a mess, general failure and disappointment.