Yup. it works. I seek out the good stuff. Lots of nutrients, compost, etc, little sand and clay. (Just to spare the pads and rims some abrasion but even lesser stuff works for the ears. I've even used roadside dirt in emergencies.)

Now there was a time when I used to adjust those famous squealers (Mafac Racers) for the right amount and decibel level. My Boston days when I didn't own a car. Ben's Revenge. When a car pulled a nasty on me, I'd hit the front brake extra hard. That squeal could be heard blocks away! Every head turns. I sit up and point to the offending car. Every set of eyes follows my point. Driver is arisen from his stupor by the squeal and looks up. Guess what? Everyone in all directions is looking - at him! Driver slinks off like a bad cat that's been caught in the act.

That squeal made riding Boston's free-for-all streets much more fun! And yes, sometimes I had to apologize to innocent bystanders when I did actually have to stop and it wasn't an emergency.

Consider this post "the dirt" on brake squeal from someone who has had those famous squealers on a working bike or two continuously for almost 60 years. (With KoolStop pads, proper toe-in and not too much wear on the pivot bushings, now rarely an issue but those old Mafac pads were fun! And like the KoolStops, they were very good stoppers while the rubber was current.)