I don't think my python is the greatest for cleaning gravel (refilling is great though, no complaints there). The suction isn't as strong as just a regular siphon. However, mine has 100' of hose sitting on the floor and then has to go up almost to the same level as the tank to drain into the sink, so I guess its understandable. Currently I use the python to drain out most of the water while I use a siphon/bucket to clean the gravel really well, until I have about 50% out. I'd never thought about just throwing the hose out the door, that's a pretty good idea. Maybe it would help. I always did feel bad about wasting the water.
I just want my planted tanks to be perfect. Is that so much to ask?
55g: (Mostly) African riverine species: Alestes Chaperi, breeding pair of Kribs, and rhino pleco
30g: Newly established reef tank
10g: Planted but fishless
5g: Unplanted with various snail species
2.5g: Heavily planted with betta.