I have a bit of experience with mock scrapes. First off, their inconsistant. some times they work great. Other times they dont work at all. i know this cuz i did an experiment with them by putting a camera looking at them. a couple of the scrapes had several bucks come to it over time. The others had NONE. some tips:
1) dont make your scrapes TOO big. its kinda like rattling elk horns together while white-tail hunting. you'll scare everything away. 2-3ft in diameter at MOST.
2)dont put it right on a trail. put it 5-6ft off the main trail. try to put it under an over hanging branch of some kind. bucks will also rub the glands around their eyes on this overhanging branch.
3) i usually us doe estrus in my dripper. never really had faith in the generic bottle they send with the dripper that just says "doe pee"
4) keep the scrape fresh. dont let it dry up and get packed down.
5) i rattle with real antlers. when i make my mock scrape, i spray on the the antlers with doe estrus and use that antler to make my scrape. the estrus not only blocks any human scent on the antler but it embeds the estrus into the dirt of the scrape. and using an antler to make the scape makes it look as real as it gets. ie: no boot prints in the scrape.
I prefer a tree stand. especially hunting over a mock scrape. cuz the bucks are at the scrape looking for the other buck, or the doe in heat. either way, their constantly looking around.
Hope this helps a little. good luck!