I feel that it makes more sense for Nidoking to not use a Choice item due to its massive coverage. I have an unorthodox set idea:
Poison King:
Ability: Poison Point
Item: Life Orb/Poison Barb
-Poison Jab
-Venoshock
-Earthquake
-Sludge Bomb/Ice Beam
This set goes all out on using the Poison status. The Life Orb is a necessity to make up for the lack of Sheer Force but Pouson Barb can be used as a substitute. Each move is kind of self explanatory. Earthquake is to deal with other Poisons or Steel types and Ice Beam is for Grounds.
That set really sucks. No offense. Not only is it completely helpless against Special Attackers who won't ever trigger Poison Point (Poison Jab's poison chance is far too unreliable), but
Venoshock isn't even that strong. Sheer Force Boosted Sludge Wave (Nidoking's best Poison STAB) is only marginally weaker and doesn't rely on raw luck to hit hard, not to mention it doesn't cut into Nidoking's Longevity. On top of this, you're going too much into mix, and that hampers Nidoking's power even further. Why even bother with Earthquake? Just use Earth Power instead so Nidoking can invest EVs into its special attack, and just put Sludge Bomb over Poison Jab, as they both have the same chance of poisoning a foe, but Sludge Bomb is actually more powerful.
Here are the calcs to prove that a Venoshock Set with Poison Point simply isn't worth it:
First off, by sacrificing Sheer Force, Nidoking loses its ability to reliably OHKO Entei on the switch-in:
252 SpA Life Orb Nidoking Earth Power vs. 0 HP / 4 SpD Entei: 361-429 (97.3 - 115.6%) -- 81.3% chance to OHKO
and if you take off the Life Orb, it can't OHKO Entei, period:
252 SpA Nidoking Earth Power vs. 0 HP / 4 SpD Entei: 278-330 (74.9 - 88.9%) -- guaranteed 2HKO
Standard Entei is Banded Entei, who WILL one-shot Nidoking with Sacred Fire, and even outspeeds max speed Nidoking:
252+ Atk Choice Band Entei Sacred Fire vs. 0 HP / 4 Def Nidoking: 304-358 (100.3 - 118.1%) -- guaranteed OHKO
It also loses the reliable 2HKO on Mandibuzz:
252 SpA Life Orb Nidoking Ice Beam vs. 252 HP / 4 SpD Mandibuzz: 200-237 (47.1 - 55.8%) -- 20.7% chance to 2HKO after Leftovers recovery
252 SpA Life Orb Sheer Force Nidoking Ice Beam vs. 252 HP / 4 SpD Mandibuzz: 260-307 (61.3 - 72.4%) -- guaranteed 2HKO after Leftovers recovery
And it loses the ability to OHKO Mega Pidgeot, who 2HKOs in return with Hurricane, thanks to outspeeding Nidoking:
252 SpA Life Orb Sheer Force Nidoking Ice Beam vs. 0 HP / 4 SpD Pidgeot-Mega: 299-354 (97.3 - 115.3%) -- 87.5% chance to OHKO
252 SpA Life Orb Nidoking Ice Beam vs. 0 HP / 4 SpD Pidgeot-Mega: 231-273 (75.2 - 88.9%) -- guaranteed 2HKO
252 SpA Pidgeot-Mega Hurricane vs. 0 HP / 0 SpD Nidoking: 235-277 (77.5 - 91.4%) -- guaranteed 2HKO
It ALSO loses reliable OHKOs on Primarina, who Hydro Pumps it into oblivion, or if it's using standard specs, it can just throw Psychic or Scald at Nidoking instead and still OHKO:
252 SpA Life Orb Sheer Force Nidoking Sludge Wave vs. 0 HP / 0 SpD Primarina: 351-413 (116.6 - 137.2%) -- guaranteed OHKO
252 SpA Life Orb Nidoking Sludge Wave vs. 0 HP / 0 SpD Primarina: 268-320 (89 - 106.3%) -- 31.3% chance to OHKO
252 SpA Choice Specs Primarina Hydro Pump vs. 0 HP / 0 SpD Nidoking: 668-788 (220.4 - 260%) -- guaranteed OHKO
252 SpA Choice Specs Primarina Psychic vs. 0 HP / 0 SpD Nidoking: 364-430 (120.1 - 141.9%) -- guaranteed OHKO
252 SpA Choice Specs Primarina Scald vs. 0 HP / 0 SpD Nidoking: 488-576 (161 - 190%) -- guaranteed OHKO
The ability of Nidoking is non-negotiable. If you're using Nidoking, you MUST use Sheer Force for it to be of any use. Your set is a gimmick that makes Nidoking weak to many things that it would otherwise be able to deal with and in turn is just not worth it. Nidoking's only set that actually means anything is the Life Orb Sheer Force set. Your set doesn't stop anything that Nidoking couldn't already stop with its standard set, and in fact makes it NOT stop things that it could with its standard set.