My opinion on the matter is there are times when scent is 100% effective and times it is not. Back in the day, a buddy and I regularly fished summer steelhead all summer, we had the drop on some fish in this weird slot that didn't look like good steelhead water but was holding fish. Never seen another fisherman at this spot. I got off work one late July day and hauled ass to the slot, we fished float and jig alot back then and I had a black and orange jig on with no scent, I casted into the slot 100 times without a touch, my buddy comes pulling up, walks the short trail through the woods after I'd been pounding on it for an hour and asks if I tried sandshrimp, told him, "nope," he says very matter of factly, " well, I'll make a believer out of you," first cast with same float, same length leader, same jig, and bam! Chrome bright 6lb hatchery, I continue casting the same setup sans sandshrimp, he tags fish, rebaits and nails another 11lb buck hatchery....lesson learned...
I've had it go the other way too, especially over highly pressured fish, no bait was the ticket, and I'd damn sure never leave home Chinook fishing without quality bait...