well.............
i dont think the cleaning loco will likely be of much use, heres why:
even on modest inclines,the trains get very heavy and are likely to run away at turbo porsche speeds.
having experimneted a bit, i dont thing you will be able to push the cleaning loco up much a grade, and to do so will likely result in heavy wear to your cog loco; going downhill, perhaps using the cog as an anchor......the problem will be to synchronize running speeds.
i think your life might be simplest with an LGB track cleaning block, if you possibly can.
the cogs will interfere with norrmal hook an dloops, the bit that hangs down. i dont know if the cleaning loco will clear, but if not, no harm.
something i have realized is that grade is an important factor. While steep incline is fascinating and dramatic, the steeper, the fewer cars you can push. You will feel this if you simply push the cars by hand, its amazing how heavy they become as the grade increases. I cannot imagine how heavy a track cleaning loco would become. perhaps, you could remove the weight from the loco, as they seem to be very hefty. I thin you will find the locomotive , with even a slight incline, will slide.
also, if you can, try to avoid or minimize curve and grade-not only drag , but alson the twist factor, ie side to side levelness of the curved track.
