I have now convinced the gravel cleaner about half a year in use and am. He is a great help when weekly water change in my Nano. With a bit of sense and caution there is no risk for shrimp and Perlhuhnbärblinge. One star deduction there is that the pumping mechanism (as already described from time to time) sometimes is something hakelig. With a little patience it sucks then at super and from there it's a self-perpetuating (Still better than the water suction by mouth or something electric with batteries). I particularly like the terminal which the hose is attached to the drain. Thus, the holding of the hose is omitted, the soil remains dry and you have a hand "to work" freely around the aquarium.
