Poliwrath isn't very viable in the current Doubles metagame (especially if you're referring to VGC16 and not Battle Spot Doubles). You can be a bit gimmicky and run it in the rain
Poliwrath @ Life Orb
Ability: Swift Swim
- Waterfall
- Ice Punch
- Encore/Hypnosis
- Protect
or just run it as a support mon
Poliwrath @ Sitrus Berry
Ability: Water Absorb
IVs: 0 Atk
- Icy Wind
- Scald
- Encore
- Protect
Either way, several Pokemon outclass it. Even its alternate evolution, Politoed, is a more viable option. There is absolutely no reason to be using this Pokemon in Doubles
On many occasions i have made Electrivire work well for me.
I think Poliwrath might do well with Swift Swim while it has a Politoed next to it for providing the rain. It's Gimmicky but i think i might get lucky.