I've been running a Rock Polish varient and it's been amazing. It's quite easy to sweep after just one Rock Polish with some support ( general team weakning, Entry Hazards, Wobb/Erufuun Encore support), can take on Dory without Return if running Jolly and no Life Orb even with +2, and Ko back with Brick Break. Even if he's put on a team without much support, he can still be a valuable member and is worth the teamslot
specficis of Rock Polish set I use
Randorosu@ Life Orb
Nature: Jolly
Ability: Sand Throw
EVs: 252 Atk / 152 Spe / 104 HP
-Rock Polish
-Earthquake
-Stone Edge
-Brick Break
The EVs give enough speed to outspeed Jolly Doryuuzu in Sandstorm after a Rock Polish, max Attack EVs to hit as hard as possible, and the leftovers are thrown into HP to give him some bulk to help survive. You could run a Yache Berry to help stop any Ice attacks from OHKOing you, but generally, Life Orb is better.
To back up my "Randorosu can beat Doryuzzu a good amount of the time" comment, heres some calcs for you people:
Rock Slide vs 104/0 Jolly Randorosu 405 Atk vs 345 HP & 216 Def (75 base power) 132 - 156 (38.3% - 45.2%)
Return deals 51.6% - 60.9%, so Randorosu is 2HKOed 100% of the time with it, but if Doryuuzu decides to run X-Scissor or Rapid Spin, you should be in good shape. Now, this calc was run with Life Orb, so a Dory running Balloon or any other item is dealing this to you:
Rock Slide: 29.6% - 34.8%
Return: 39.7% - 47%
Only Return has a chance of KOing after Stealth Rock. But in order to accomplish this, Doryuzzu needs an Adamant nature. If Dory decides to run Jolly, the damage output is even lower:
With Life Orb:
Rock Slide: 31.3% - 37.1%
Return: 42.6% - 50.4%
without Life Orb:
Rock Slide: 24.3% - 28.7%
Return: 32.8% - 38.8%
all these calcs show that without a Swords Dance boost, the only times Doryuzzu is going to be KOing Randorosu relibily is when he runs Return with Life Orb.
Now for +2 calcs. same items as before:
Adamant Life Orb Return +2: 103.2% - 121.4%
Rock Slide with same spread: 75.9% - 89.6%
This may not seem good, but remember, quite a few Doryuzzu's run Balloon to switch in on Ground moves to try and get a Swords Dance, so lets see those calcs.
Adamant Return without Life Orb +2: 79.4% - 93.6%
Rock Slide: 58.6% - 69%
So without Life Orb, Randorosu can switch in on a Doryuzzu with a Swords Dance either by getting in on Earthquake or getting in as it Swords Dances, survive if Doryuzzu lacks Return, and KO with Brick Break. Now for the Jolly calcs:
Jolly with Life Orb +2 Return:93.9% - 110.7%
Rock Slide with same scenario: 69.3% - 81.7%
Now, Randorosu isin't left off much better here then with Adamant, besides being able to survive a Rock Slide, but theres still the No Life Orb Jolly calcs:
Return: 72.2% - 85.2%
Rock Slide: 53.3% - 62.9%
Now, Randorosu can survive any +2 attack and KO back with Brick Break, although Randorosu can only switch in on Earthquake or while Doryuzzu is Swords Dancing.