As opposed to kinking the hose to pause the syphon, I prefer to hold my thumb over the end that's in the bucket. Gives much greater control as well as not damaging the hose. Allows you to pause the flow at any time so you haven't half drained the tank before barely getting started with cleaning the substrate, can pause the flow if a fish/shrimp etc gets too close or gets inside the bell part, letting them swim back out, and means you can remove the muck without sucking up the sand.
If the substrate is sand only, you don't need to stick the bell part down into it. Just swirl it above the surface and the muck should lift off. The times I do want to clean deeper into the sand, can do that by using your thumb over the end. Let the sand get sucked slightly into the bell part, thumb over end stops it being sucked all the way through, release and replace thumb briefly and the murk will go up while the sand is allowed to fall back down. Move bell to another section and repeat as needed.
I'm positive I linked this video to you before, but I don't think you watched it. He shows you how to clean gravel first, but if you keep watching he shows sand as well. Cory does the kinking the hose trick, I use my thumb over the end, but the practice and result is the same.