Laughed at this because I'm the guy who bought the fancy injector kit first before trying the cheap tubes. Wasted a whole afternoon on my driveway with that thing, got epoxy all over my hands that took a week to peel off, and honestly the six dollar squeeze tube would have done the same job. The real trick is exactly what you said, scraping the crack out with a wire brush and getting the loose junk out before you fill it. Half the people who complain about cheap filler just squeezed it into a crack full of dirt and leaves and then acted surprised when it popped out. Dave probably spends two hours because he's scrubbing and prepping anyway, he just also drags out a bunch of tools to feel fancy.

Used to scrub mine too, now paper towel only. Never going back.