I think it would likely end up being a waste of your time TBH. There is a reason tv's are set to torch mode in the store environment. When customers shop they look for the brightest most colorful tv, rarely do they look for the most accurate. If you ended up doing calibration services for that stores customers, it would be wise to have a few tvs calibrated just so associates can demo the differences to willing customers, but in general when people shop they don't shop for accuracy so the store would probably leave the tv in Vivid/Dynamic and only switch over to demo calibration benefits. Trust me, i've worked retail selling tvs for 7 years now and know what customers look for when they shop.
I'll admit i'm guilty of this habit as well in looking at the brightest tv. It's only natural as our eyes are naturally attracted to brightness and color. When I bought my VT50 the store had it in THX mode and even though I knew it was the best tv on the shelf, THX mode looked like crap in the store and I couldn't help but catch my eye peaking at the other sets in vivid/dynamic. Had I not known better like the average consumer, I would've skipped right over that tv.
For the record, I use THX mode in home and love it, by far the best looking setting in home aside from a real calibration.