Yea, I am not sold on SmashPassing - it becomes more about the strategy than Nidoking itself. Eggbert hits the nail on the head - yea, Nidoking would benefit from receiving Shell Smash boosts, but you're better off having other mons on that slot anyways.
I feel like SmashPass teams are too one-dimensional in the way they play and will defeat the purpose of team-building. It's essentially 1-2 Smash Passer, 1-2 Dual Screener, 3-4 recipient Sweepers. Nidoking would simply be one of the sweepers, who may not even see much play, since the boost may very well be passed to bulkier mons.
I agree with Zurich that if we're adding a SmashPasser, it should be part of bulky offense rather than the overlying strategy.