I don't bother to bag the hops. I used to, but at some point I started adding three or four hop additions to a batch. Bags aren't free, and that adds up. Being the cheapskate that I am, I just didn't want to pay for them. So I stopped using them, and nothing bad happened. Haven't bagged them in years. Nor do I strain. My method of aerating is to pour from the pot into a bucket, then through a funnel into the carboy. Doing long, slow pours. Well, that gives the hops an opportunity to settle to the bottom and be left behind. But other than that I don't try real hard to separate them. They just become part of the sediment. No big deal.