you're right, you don't need a stir stick. Instead, you need masking tape and paper so you don't get overspray on your car.
You also can't be as accurate with where you want the paint to go precisely on the brakes.
Why reapply when the cheap stuff wears out? Just do it once and be done with it.
No doubt it costs more, but let's be realistic: $40 for a ONE TIME application is still a REALLY CHEAP mod.
what do you do in 1-2 months and the brake dust has corroded the paint job?
My $4 looks great 2 months later