@ kd24, Whilst Gyarados is a remarkable pokemon to use in a stall team, I found when using the set that he becomes overwhelmed late game if the opponent has a counter for it, (e.g. I've seen Jolteon/Zapdos hanging on most OU teams recently) therefore he isn't in my opinion sustainable in a stall team, because there is little or no chance to use Gyarados effectively. However in some games Gyarados has come out on top, and has been effective. But I find that Gyarados is a "old trick" that either works in "RestTalk" or is just completely put down.
On regards to Dusknoir, I find that it works effectively as a stall wall/tank, and is a viable counter to the oh-so-common-Blissey, and can cripple most / all physical based pokemon, with the common set: Will-o-Wisp/Shadow Sneak/Pain Split/(physical filler; earthquake/ice punch). But then Dusknoir's use can be subjective to style of play. Futhermore within a stall team, where hazards become a necessity, being typed Ghost, Dusknoir can obviously act as a spin blocker.
sure we all want to be the very best. not me. i just want to live forever.