MR do you use Belly Drum on your Azumarill? Literally the only set I see everywhere is Belly Drum / Aqua Jet / Play Rough / Superpower.
Although I still think Huge Power Belly Drum'd priority STAB Aqua Jet with 252 EVs in Attack and HP holding Leftovers is pretty hard to counter, IMO.
Why am I telling all of you, how to beat my Azumarill?
Manus is down. I'm stuck between trying to kill the hydra in the ash lake and that black dragon. And eventually Gwyn.
EDIT: You also didn't really tell me how to beat Azumarill, you told me what not to do. That list can go on for a while.
Hydra died thanks to that steep dune letting me get close while it lunged at me. Dragon's up next.
A multiscale Dragonite laughs at fairies that aren't Azumarill and Mega Mawile.
Let me educate you in what Burn does. It lowers attack by 50%.
Lesson 3: Don't bother with Status. Your only stating the obvious.
Sleep is the best as it's mostly reliable and gives you many free turns. The next best would be Frozen.
If you had to use one against Azumarill, Burn would be the best choice if you can put it to Sleep.