I can’t imagine anyone preferring a mechanical pump over gravity when a gravity flow can be established, nor is there a more effective method of disposal than gravity…
The slinky is much more pleasant to work with that cleaning and repairing a pump… and who are you trying to kid about the pumps hose… every time I role up my fresh water hose up some residual water runs out of it to, and the volume isn’t much different than what drains from the slinky and is much less than what would drain from a 100’ garden hose… I know of no maceaitor pump that comes with a hose dryer option…
If I owned a CG the sewer solution unless they have been much improved would not even be allowed… they waste more water than was used… water and sewer treatment are becoming exceptionally expensive too much so to waste when simple gravity works well…