Yes, I've used that principle before; ask a question you know should be "no" and see what happens. Can that car tow this (way too heavy) thing? Will my dishwasher clean my dishes even though my water is full of sulpher? Will this (integrated graphics) computer play $LATEST_GAME at full settings? Will this plastic thing last ten years of solid use outdoors?

In my personal experience, I actually don't get the full-throated lie "Yes!" all that often, if ever, but I get a lot of uncomfortable waffling.

Indeed. In buying a new car some years back, I found a reliable way to translate answers. When the dealer answered, "Yes" it was generally truthful. But when they answered, "I think so", the actual answer was definitively "No".