I've gone from 2k to 300k with silicone. Also tried Exceed cleaning putty.
I've gone to lighter fluid, but the chassis set up works with the setting. I would watch gear wear, as they are aluminum and with the power and grip from the tires and engines, puts a real load on them. However, when I had thick fluid or putty, you point it where you want it to go hit the throttle. I do not like a spool in electric touring, so have never tried. Normal rules don't allow one ways or, Thorsten or electric gear boxes. Locked up gears done with the stock stuff should be allowed.
With the heavy fluid or putty, you need to watch the gear case, as you can pull the screws out. I have two fixes, but the best is build with a new case.