What is the best mini aquarium vacuum for a 2.5 gallon tank with gravel?

I have two 2.5 gallon aquariums with gravel, live plants, and 1 Nerite snail each. I hate using hand pumps or siphoning tubes to clean - they ALWAYS break, stop working, or get clogged. I alwats end up having to take everything but the gravel out, try to suction what I can while constantly unclogging, and end up having to replace almost all of the water because it's still sucking while I'm trying to unclog. What is the best battery-powered or electric vacuum for a tiny tank?