I'm not really talking about the size of the tank more than the innovation behind it. Would the vacuum that is created cause the bacteria to be removed quickly or would it stay somewhat in the gravel?
Bacteria won't matter in a bowl like that. The whole point is to do large ( 75+ or even 100% ), weekly or biweekly water changes for a betta. That being said, I don't think the vacuum affect would be any stronger than a siphon which does not vacuum bacteria off of substrate.