Just finished up with my first dry hop brew. Midway through I read a post about adding marbles to the hop bag to make them sink. I used that info for the second dry hop, tied the first hop bag to a piece of stainless pipe to make it sink. Hops fight bacteria naturally so doing the standard sanitizing with the other fermenters/ components should be good. My brew went through primary, secondary and tertiary fermenters with hop & sugar additions without infection. I siphoned off both fermenters by actually putting my siphon into a fold of the hop bag to further filter the beer, eliminating almost all of the trub.
Dry hopping & late hop additions are wonderful, great, fantastic, beautiful ways of increasing hop flavor.. Can ya tell I like hops?