I’m a firm believer in positive reinforcement, so I would never use any method that scares them such as squirting water or loud noises. Rather, our house is dog proof, so rarely will you find food in reach of a paw or mouth.
Simon and Katie were both counter surfers, and a short quick “down” command along with praise as soon as they got down worked for them. Emmy is still a counter surfer, but only when it’s time to eat now, so vigilance works as she runs into the kitchen. Plus she must sit and wait for the “ok” command before she can eat her food.
Now I can leave an empty plate in the living room, and none of them touch it.