I often dryhop, and I don't worry about sanitation. I keep the hops in the freezer, and they go from vacuum sealed plastic bag (done with the foodsaver) right into the carboy. So far, so good! I got at least 24 ounces (dried) off the cascade plant this year, and 16 ounces (dried) last year, so I've been using them pretty often. I only have done one beer with the homegrown hallertauer and that worked fine, too.
Broken Leg Brewery
Giving beer a leg to stand on since 2006