I haven't dry hopped anything yet (though my next beer will be an IPA, so keep me informed :)) but I have heard that putting them in a hop sock will help prevent clogging when you rack off the hops. You get less utilization, yeah, but it seems like a small price to pay.
I suggest using pellets instead of leaves. Also if you use a muslin bag with some copper or stainless that is equal weight to the hops then it will be able to move around in the brew instead of float on the top. I picked some of that up from brewing network and some from trial and error.
Thanks for this. I actually went ahead with some Simcoe cones cause I already had them bought. I read a little bit of advice from Vinnie Cilurzo of Russian River Brewing. His big advice was to cut it off from light completely and to create a CO2 blanket. I put some duvatine over the carboy to black it out completely and I've just been swirling the carboy a bit to get the air moving. Looking forward to seeing how it goes. Was going to leave them in for a week. Any other suggestions on timing?
I've dry hopped in primary only, secondary only, and in both. You won't get too much difference between 1 and 2 weeks that you wouldn't get via the normal maturation process itself. As with anything, give it a try, record results, tweak as needed, relax, and have a homebrew.