I dont think I ever used Azumarill but I would use a redirector. I chose redirectors if you come against a Pokemon you cant OHKO with aqua jet, so I have two Pokemon that might fit the role.
Indeedee-F @ Sitrus Berry
Ability: Psychic Surge
Level: 50
EVs: 252 HP / 212 Def / 44 SpD
Sassy Nature
IVs: 0 Atk
- Expanding Force
- Follow Me
- Helping Hand
- Protect
Choose Indeedee-F if you want a Pokemon that can somewhat deal damage while still supporting. Its has less health then the next Pokemon but is rather well rounded in its stats (besides attack.)
Amoonguss @ Rocky Helmet
Ability: Regenerator
Level: 50
Shiny: Yes
EVs: 252 HP / 184 Def / 72 SpD
Sassy Nature
IVs: 0 Atk / 0 Spe
- Pollen Puff
- Rage Powder
- Spore
- Protect
Pick Amoongus if you want to absorb some of Azumarills weaknesses like poision and grass. I also put pollen puff in there if you really want to heal your teammate. However looking at its defenses its a little less well rounded but can still can take hits.