Well, he looks pretty good, might want to consider invest some of those Hp EVs into his Def, for more well rounded bulk. I would suggest replacing Outrage and Bulldoze for Dragon Tail and Stealth Rock, if you really don't want to go the phasing route, then leave out the tail for Earthquake ( Bulldoze just.. no.. )
252 HP Evs and a Life orb is pretty contradictory, I would switch that to Leftovers, because of the fact that he will also die off quicker.
I'm seeing some major problems here, hate to say. HP Fire ( Failness, use Flamethrower ) and a solid item ( Life orb ) will benefit you more in the long run then Techno Blast and your Cassette. Tri attack gives 0 coverage, give it Ice Beam to give yourself a complete bolt-beam combo, which gives MUCH better coverage here. Psychic is pretty bland, it gives some coverage, but an STAB Bug buzz would work better.
While Drill Run has a high crit rate, Earthquake has higher power and accuracy, with together become much better than just that crit rate. Poison Jab covers grass, that's it. And covering 1 type isn't much to brag about, so I suggest using Brick Break, to achieve the well known Fighting + Ghost coverage, which similar to Bolt-Beam, is amazing.
Well, A. Zoom Lens doesn't increase accuracy, that's Wide lens, and it only increases by 10% of the move's accuracy meaning you're at 88 and 77, which is still really bad.
I wouldn't run a Mixed-Pert, it just doesn't work. If you want a special route, try this.
252 Sp Atk, 128 Sp Def, 128 Hp
HP of choice.
252 Atk, 128 Def, 128 Hp
Brick Break or Stone Edge
Focus Sash + Bulky Pokemon = Bad idea
Focus Sash + Sandstorm + Pokemon that gets hurt by sand = Bad Idea
In other words, remove your Focus Sash here, Dusclops is meant for bulk.
Give it an Evoilite, that actually makes it much more bulky.
I see where you're trying to go with this, but Dusclops can't play suicide well, and it's hard to pull off in the sand, and really shouldn't be tried in the sand. I would suggest replacing him for Golurk, but if not, try this set out instead.
252 Def, 252 Sp Def, 4 Atk
Now, I wouldn't suggest using Dusclops at all, but if you're die hard for him, here's the set to try, Substitute and Curse will both lower your Hp, giving yourself a big boost from Pain Split and dragging your opponent further down. Focus Punch + Substitute is good for him, and covers his dark weakness.
Now, Golurk would be a much better choice, using...
Golurk @ Chesto Berry
Role: Sub Punching Beast
Trait: Iron Fist
EVs: 200 HP / 252 Atk / 28 Def / 28 SDef
Brave Nature (+Atk, -Spd)
Magic Guard makes it to where he won't take Life orb damage ( 30% power boost for all moves that doesn't wear off... ) so use that instead of Psychic gem.
Timid Nature over Modest, Alakazam has the power, he needs more speed.