While the rep's idea may seem very clever, all sales people have to weigh the risks vs. benefit of any portion of a presentation with humor, sarcasm, double-entendre or parody. There also are many other variables that are important to consider. The type of industry you're in is a significant factor. For example, if you deal with more serious, high-end goods and services, you must be cognizant of the fact that some presentation elements would be inappropriate. Without question, the most important aspect to consider is the audience itself.
College graduates have different perspectives from high school dropouts.
Remember men are from Mars and women are from Venus. Gen-Xers have a very different take on things compared to those over 65. Rural vs. city. While some people would find the handcuffs funny, other customers may be offended by the reps' corny remark and get turned off to the rest of the presentation. Ultimately, you are the one to make the judgment call.