Scent drags are a waste of time for a mature buck. You might get a spike or 2 year old to follow, but an old buck will cut your track and run.
They smell everything. The oil on your skin, shed skin cells, the dog **** you stepped in last week, the laundry detergent from your socks, the fresh soil and broken foliage in your footsteps. They will know a human was there for days after.
A lot of scrape activity is done at night. If you can find a scrape close to bedding (it'll usually be a big one, like the size of a car hood, used by multiple bucks), and can get set up on it with good wind, you'll have a good chance.
I don't use any scents, and play the wind. You can't fool a deer's nose. I like early and late season when they're on a bed to food pattern that's predictable. The rut isn't predictable. About all you can do there is setup downwind of a known doe bedding area, bucks will cruise through scent checking from a distance. You can use the terrain to your advantage, funnels or choke points like you said along a buck's route are good bets. This applies best to the seeking phase, once you get into lockdown when most does are in heat, go back to hunting beds.
Also keep thermal winds in mind, hunt high in the morning, low at night. If you're setup on a hillside in the afternoon overlooking a draw, your scent will go straight down the tree into the draw, regardless of predominant winds. In the morning, when things are warming up, your scent will go straight up like a chimney.
Big bucks love to bed on hillsides with predominant winds coming over their back, and thermal day winds coming up the hillside to them. They've got it made there and it's near impossible to get the jump on them. A buck will have different bedding areas to suit different wind conditions.
We are still about a week away from peak rut, this year has been strange, not a lot of activity on cameras from bucks and very little sign. They have been doing a lot of culling with CWD and the populations are down quite a bit.
