Raff,
There used to be a guy who fished Dry Falls who did the same thing. He's use a type 7 full sink line. Cast it out and would sometimes wait 10 minutes before he'd start to strip in. When he did strip, he would put his rod completely in the water, pointing straight towards the bottom. Only his reel, handle and about a half foot of the rod were above water. He'd twitch the fly in super slow and just killed the fish. I swear one day I saw he catch at least 50 bows doing this. I spoke with him at the launch one day. He said all he ever used for doing his was chironomids or hares ears.
Brian