Scrape hunting is effective, if you know the scrapes are active, and you can stay downwind and well hidden. A treestand will give you a much better chance at a buck that is tending a scrapeline, and you will be able to get a closer shot. You should also know that if you choose to hunt from a treestand, you will need to aim higher on the animal to hit the vitals. Aim just a few inches below the backbone. If you were standing on the ground you would aim just behind the forward shoulder, in the center of the chest cavity, to hit the vitals. But in a treestand if you aim in the center of the chest cavity you may not kill the animal. Think of it this way, the slug will go in where you are aiming but will come out low, because you are shooting down, so to compensate for shooting down you need to aim higher than you would if you were shooting from the ground.
You will find that a mature buck will check his scrapeline, early morning, or late evening. Possibly more, depending on the buck to doe ratio, and how far into the rut.
Be careful if you choose to use a stand, safety should be your first concern, when using a treestand.