Dave it is a 2 way street...dont sweat it.
i dont even target resi work, yet in 8 years of doing VLM, out of the perhaps 200 homes i have done, i estimate maybe 10? of those new clients hired me because i was not using HWE. they had a bad experience with a hack who left it too wet / wickbacks. so out of those 10 ppl, you know at least several told a HWE cleaner the same thing your prospect told you Dave, "do you use the method with the hoses and wand? ahhh ok, sorry to waste your time *CLICK*"
no biggie. the only way you will never hear that again, is to offer both cleaning systems.
i'm perfectly happy offering 1 system , because it pays the bills and provides for my family nicely, with no down-time