Dig has a pretty big wind-up time before you actually go underground, so you're really vulnerable to speedsters. I don't think I'm good enough at the game to pull it off with a giant like Garchomp—especially since everybody and their mother is running Greninja or Lucario, and near all of them have Ice Punch.

I'm having a lot of fun doing it with Hawlucha, though. Flying Press, Bounce, Fly, and Dig are all available. Watching her pop in and out of combat, over and over again, with opponents wasting moves each time, knowing they have to re-target her every time she does it, is extremely funny. I don't have a massive win rate with it, but it's hilarious, and that's way more important than ranking.

Update:

Hawlucha dipping in and out constantly has gotten me to Rank A. There's a lot of people with clearly modded consoles at high ranks, though.

Think: "Yeah, my team is all shiny alphas with perfect IV's, for Pokemon that don't have naturally spawning alphas in this game, so I definitely lucked into this happy 1 in 111,974,400,000,000 chance team, not accounting for how I got these exact three on-meta spawns, which is frankly incalculable without data mining the game's code."

It's very annoying.