Thusly "NetMax" Spake Unto All:

Discounting their hydrogen peroxide, potassium permanganate, chlorine,
ozone and bleach treatments, they talk about aeration, and make mention
of an iron reducing valve having variable effectiveness (improves as the
water is more acidic).

Yeah, degassing is more effective at lower pH's. However hydrogen
peroxide could help with the smell. I presume you know about devices
like this?:
http://www.malawicichlidhomepage.com.../oxydator.html

;~). fwiw, I'll take your advice if the exchange is fruitless, but
regardless of the outcome, it was worth asking them to stop... the cause
justifies the effort, eh?

Just be careful. I know from personal experience that guys like these
can cause real-world effects.