I've done some testing with this team in PO and have gotten some pretty positive results. I'd like to make this team in the actual game but I figured I'd have the Smogon community tell me what they think first.
Politoed @ Choice Scarf
Ability: Drizzle
Nature: Timid [+Spe -Atk]
EV's: 4 HP/252 SpA/252 Spe
-Ice Beam
-Scald
-Focus Blast
-Hypnosis
Very standard scarf Politoed set. Loves putting opposing leads to sleep (although the accuracy is shaky) and can work as a potent revenge killer, I've even managed to do some late game sweeping with him on rare occasion. Obviously sets up rain, the crutch of this team. The biggest problem I've seen is him leading against an opposing weather starter. He is almost always faster with his scarf, making the opposing weather effect go up 2nd.
Accelgor @ Mental Herb
Ability: Hydration
Nature: Jolly [+Spe -SpA]
EV's: 252 HP/4 Def/252 Spe
-Rest
-Agility
-Acid Armor
-Baton Pass
The ninja bug serves me perfectly as a baton passer. His ability Hydration and his Mental Herb together in the rain keep any condition from interrupting his passing. Every member of my team greatly appreciates +2 speed or +2 Defense, or sometimes both. The HP EV's allow him to actually take 1 or 2 hits before he passes and any damage can be easily remedied with Rest, which he wakes up from immediately if rain is up. I ran Substitute on him for a while, but it was almost never actually beneficial, as it would usually get broken before he could pass it, or right as he passed it, making it a wasted turn.
Nidoking @ Life Orb
Ability: Sheer Force
Nature: Timid [+Spe -Atk]
EV's: 4 HP/252 SpA/252 Spe
-Thunder
-Earth Power
-Ice Beam
-Surf
Nidoking is my favorite recipient of Accelgors boosts. With access to a Sheer Force/Life Orb boosted Thunder, Earth Power, and Ice Beam (Thunder being 100% accurate in the rain) he has been known to sweep through entire teams. Surf is actually his most powerful attack when boosted by the rain, although it does not receive a boost from Sheer Force and thus you take Life Orb damage from it. He's also immune to Thunder Wave and Toxic and burns don't hurt his attack. Any water attack tears through him, but if he's gotten an Agility boost he can usually take out water types with Thunder, otherwise I can just switch to my next poke.
Toxicroak @ Leftovers
Ability: Dry Skin
Nature: Jolly [+Spe -SpA]
EV's: 4 HP/252 Atk/ 252 Spe
-Swords Dance
-Drain Punch
-Sucker Punch
-Stone Edge
As every rain team knows, Dry Skin Toxicroak is very tough to take down when used correctly. Drain punch only adds to his durability, while doing decent damage at the same time (especially after a Swords Dance). The set overall is pretty standard. I ran Substitute on him for a while, but the coverage that Stone Edge offers has benefited me in many more scenarios.
Scizor @ Occa Berry
Ability: Technician
Nature: Adamant [+Atk -SpA]
EV's: 252 HP/252 Atk/252 Spe
-Swords Dance
-Bullet Punch
-Bug Bite
-Brick Break
Occa Berry + Rain has Scizor happily boasting no weaknesses. A nasty surprise for anyone trying to throw a fire attack at him as he chuckles and SD Bullet Punches. Bug Bite and Brick Break are mainly for coverage, although their secondary effects can come in great handy in rare situations.
Dragonite @ Leftovers
Ability: Multiscale
Nature: Modest [+SpA -Atk]
EV's: 4 HP/252 SpA/252 Spe
-Hurricane
-Thunder
-Dragon Pulse
-Roost
Dragonite loves Accelgors boosts almost as much as Nidoking. Multiscale and Roost make Dragonite very bulky and firing off 100% accurate Hurricanes and Thunders is no joke. He can also serve very well as a dragon killer with his ability multiscale. If he is at 100% HP, few dragon attacks can OHKO him (aside from Haxorus with his ability Mold Breaker) and he can kill back with Dragon Pulse (This works especially well on any opposing Kingdra trying to take advantage of the rain).
There are a few obvious flaws to the team. There is no grass or fire move on the team to speak of. I have no way of getting rid of entry hazards (Although I feel it should be mentioned that 5 out of my 6 are immune to Toxic Spikes). I also don't have a way to set up my own entry hazards, but I feel like that isn't as much of an issue. Opposing weather teams have caused a few problems for me before. For this reason I tried including a Lickilicky designed to take out other weather users, but he was mostly dead weight on the team against anything else. Hope I formatted everything correctly, if I didn't, just let me know. Happy rating!