Well considering your faith in Midas I would take it back and go with them on roadtest to insure tech hears the noise.
A clean and adjust on rear drum brakes is a rip-off IMO since they have auto adjusters.
Sulphury smell usually comes from exhaust, not brakes.
p.s. Suggest you also try slow speed test using handbrake only to stop car to see if there are any change in symptoms.
