I won't use my homegrown hops for dry hopping anymore. I lost two batches from it. I disagree with the oft-repeated idea that "hops are naturally anti-bacterial so you don't have to worry."
When I go up to cut down my hops for harvesting, many of them get on the ground. There's plenty of dirt that can come into contact with the hops. Or what about insects? insects getting into your dried hops can carry all kinds of contamination. Hops being "naturally anti-bacterial" will not matter if there's chunks of soil keeping the hop oils separate from a source of contamination, or have any effect on an insect's body, or any number of other potential problems.
All that being said, I'm not sure why commercial hops would be any more sanitary unless they use some kind of heat treatment, which would possibly be problematic and potentially destroy sensitive aromatic oils anyway. I do dry my hops on low temperatures, maybe I'll try a higher setting on my dehydrator next time.
All that being said, some people do it successfully, but I'm reluctant to risk another batch after losing two in years past. You might have more luck than me.