Very, very late, but here's my favorite Slowpoke set:
Slowpoke @ Eviolite
Ability: Regenerator
Level: 5
EVs: 116 HP / 76 Def / 116 SpA / 196 SpD
Calm Nature
IVs: 0 Atk
- Flamethrower / Fire Blast
- Future Sight
- Teleport
- Slack Off
Fire Blast is an option because it can KO Grookey on the switch if rocks aren't up.
116 SpA Slowpoke Flamethrower vs. 0 HP / 0 SpD Grookey: 16-20 (76.1 - 95.2%) -- guaranteed 2HKO after Grassy Terrain recovery
116 SpA Slowpoke Fire Blast vs. 0 HP / 0 SpD Grookey: 20-24 (95.2 - 114.2%) -- 56.3% chance to OHKO
Fire Blast also has a better chance at 2HKOing Pawniard and has a great chance to OHKO Magnemite with Stealth Rock chip damage.
Flamethrower is good enough to KO Ferroseed after Rocks damage and Future Sight damage. It also has way better accuracy than Fire Blast.
Slowpoke's weakness to Knock Off makes knock absorbers like Mienfoo, Pawniard good teammates. It's also weak to U-turn users like Scorbunny, Larvesta, and Mienfoo, so Koffing is also a team option.
