If you do it five times with some intelligence, you have rules that you can apply and have most things work most of the time from then on. It's really not a huge hassle and generally the malware-containing networks aren't the ones you are greylisting.
Yep, I do that often. It's apparently a very underrated tool because it can pretty much download most of the video content out there on the internet at large. But many people have no idea about it, even technical people.