The lesson
Script the demo as a timed agenda that ends in a before-and-after the buyer can see with their own eyes.
A deck rebuilt by Pitch Unfairly opens "No lines. No feet. No kidding." under a tape-measure border. Slide four slides between Without, Side by side and With on the cream pants. Slide five's agenda reads "Give me ten minutes and one ladies' room": Minute 5 is a field trip, Minute 6 "White pants, without.", Minute 8 "Same pants, with."
The ladies' room stunt and the figures belong to this story. Keep the timed agenda, the quoted customer line and a before/after control that does the proving.