I believe the drippers attract deer, bucks and does alike. My best advice is to find an active scrape fairly deep in the woods/brush. Most scrapes alond field edges will be visited after dark. Those that are in the woods offer you the best chance to have a buck visit in daylight.

I hung a dripper last year and had pretty good results (lots of photos) with it. But, to be honest like BH said, peeing in one works just as good IMO. The scrape I watched last season was near my stand. Every night I left my stand I walked over and took a whiz in it. My camera showed I had plenty of action in the next couple of days.

But, I have taken whodeys approach this year. Less is more sometimes. My camears are not near my stand this year and my scent dripper lays on a shelf in my garage. I've hunted three days so far this year and could have killed four deer already.