Damppchaser Humidifier Treatment = bactericide?

[J Patrick Draine]

Dear Damppchaser Experts (you know who you are):
While trying to sell my customer a Damppchaser system for their Yamaha GH-1
located above baseboard heat ("Oh its the only place we could possibly
place the piano ..."), she immediately replied that she is Very Wary of
humidifers of any kind due to her fear (paranoia) that they will be a
breeding ground for bacteria (i.e. she's paranoid that everyone in her
family will die of Legionairre's [sp?] Disease).
I immediately retorted that, well, there's an additive to the water (the
Damppchaser Humidifier Treatment) which prevents that. Her response was
basically, "Prove it!" I told her I'd send her some literature.
While the chemicals enumerated on the bottle are ceratinly poisonous to
humans, it does not say they are bactericides. The benefits listed on the
bottle are "Improves humidifier pad life and helps to prevent fill tube
discoloration".
Was I "pushing the envelope" in my answer to her? Is there a technical
bulletin or customer soothing p.r. sheet which clarifies the situation?
Thanks in advance,
Patrick Draine
Billerica, MA