Tired of laying hazards only to have them spun away? Dusclops is hands down the best source of Rapid Spin protection. Its immunities to Normal and Fighting greatly benefit many teams as well, especially stall teams. Though its HP stat is low, Dusclops's immense defenses let it survive many attacks. It has a number of tricks at its disposal, and can generally be a prick with Pressure.
Dusclops is good for a few things, but your main reason for using it will likely be its ability to spinblock. In fact, barely any spinners can get past it. It is one of the reasons people run Magneton instead of a hardy spinner, and forgo Claydol for Donphan, who can hit Dusclops hard on the switch with a STAB Earthquake off base 120 Attack.
Anyway, the premise is simple: block Rapid Spin, burn opponents, and when low on health, Pain Split or Rest. Dusclops even beats Blissey flat with Will-O-Wisp, Pain Split, and repeated Focus Punches. Even if Blissey attacks with Ice Beam, the burn will force it to recover eventually, and Dusclops will land a Focus Punch.
36 Attack EVs guarantee Shadow Ball will OHKO Alakazam, while maximum HP is a must due to Dusclops's low HP stat. The remaining EVs can be split between Defense and Special Defense depending on what Dusclops needs it for. Defense EVs help a lot against Donphan, Heracross, Medicham, and Snorlax, while Special Defense investment buffers hits from special attackers such as Blaziken, Starmie, and Alakazam. Finally, one can run use 48 Speed EVs to outspeed Snorlax.
A pretty decent Salamence counter, this Dusclops also stops Donphan pretty effectively. Watch out for Suicune, however, as it will Roar Dusclops out, and Milotic, who can take advantage of the burn and use Hypnosis to put Dusclops to sleep. However, if Sleep Clause has already been activated, Dusclops can Calm Mind up to take less damage from Surf, and then Pressure stall it with Rest.
ThunderPunch and Fire Punch are alternative attacks worth considering on this set. Maximum HP is still a must, and EVs should be concentrated in Defense as Calm Mind will boost Dusclops's Special Defense anyway.
With Shadow Ball, this is one of the best Gengar counters in the game. Even if Gengar has Hypnosis or Will-O-Wisp, Dusclops can function as usual, and maybe even surprise a physical attacker with a Sleep Talk Will-O-Wisp. It's also a great sleep absorber and switch-in to Pokemon such as Breloom and Jynx.
As with the first set, 36 Attack EVs make Shadow Ball a guaranteed OHKO on Alakazam. 252 HP EVs maximize Dusclops's low HP stat, and the rest balance its defenses.
Toxic is an alternative to Will-O-Wisp if you prefer poison to burn, but there are many more effective users of Toxic than Will-O-Wisp. Imprison can prevent opponents from using Rest or a status move, while Snatch grabs useful support effects such as Blissey's Softboiled. Counter can let Dusclops catch some threats, such as Curse Snorlax and Choice Band Guts Heracross, off-guard. Hidden Power Flying can be used if you desperately need a Heracross counter, and it also helps against Breloom and Machamp.
There are two main advantages to using Rest over Pain Split: in addition to healing it fully, Rest also cures Dusclops of status. Pain Split, on the other hand, heals Dusclops without putting it to sleep, and will also lower the opponent's health. It can even bring the likes of Blissey and Snorlax to well below 50%, and almost fully heal Dusclops when used against most healthy enemies. However, Pain Split will not be as effective against weakened opponents. With Pain Split, Dusclops will also find it difficult to actually KO its opponents, because it will be worn down alongside them, and its low Speed leaves it unable to deal a fast final blow. Rest is also the better move for PP stalling, which Dusclops does very well with its high defenses, access to Will-O-Wisp, and Pressure ability. Additionally, Pain Split doesn't remove status. Some Claydol carry Toxic, so Dusclops will likely need Rest or cleric support to reliably block Rapid Spin for long. Even if using Rest, though, Dusclops appreciates cleric support, as it removes the biggest problem of Rest: the two turns of sleep.
Checks and Counters
Houndoom can come in on Will-O-Wisp or Shadow Ball easily and has both Crunch and Pursuit; the former hurts Dusclops if it stays in and the latter if it switches out. Tyranitar has to avoid Will-O-Wisp at all costs, but he can Substitute or Taunt, Crunch for a load of damage, or set up Dragon Dance boosts. Both of these are taken care of by a swift Focus Punch, however.
Skarmory doesn't take much damage from physical assaults, and is not 3HKOed by Seismic Toss or Night Shade. A burn reduces Skarmory's damage output, but most of the time he will handle the damage just fine, and can set up Spikes in the meantime. Suicune survives five Seismic Tosses, and can Calm Mind up and KO with Surf. Milotic can switch in on Will-O-Wisp to activate Marvel Scale, and use either Toxic or Hypnosis to cripple Dusclops. Milotic cannot outright KO Dusclops, though.
Guts Pokemon, namely Heracross, Ursaring, Swellow, Hariyama, and Machamp, can take advantage of Toxic or Will-O-Wisp. Although their best STAB attacks won't work well—or at all—on Dusclops, their coverage moves nonetheless do a number on Dusclops; they can then proceed to clean up the rest of your team.