You can dry-hop with one of those hop socks you boil in. Weight it down with some marbles. If you are dry-hopping in a carboy, it might be advisable to tie some fishing line around the bag to help with removal. You could also just drop the pellets in, and then attach a paint strainer or mesh bag to your racking cane to filter when siphoning to the keg.
Another option for you might be just to do your secondary in the keg, dry hop with a bag and just pull it out when you are done.
Another option is to dry-hop with whole hops if available. I personally like this method better, because it avoids most of the small pieces.