I have had two occasions where people offer free sample cleanings by Kirby. They try to come across as friendly and non-threatening but I am a quick study.
The guy shook my hand and had a limp shake which told me this is a scam. He was aggressive with this sales pitch but shakes hands like he is delicate? I would be more concerned about people wanting to get in my house to case it and then come back and rob me.
I could care less about the carpet scam. I advise people to not let any stranger in their home.
Good simple rule.
They also knock that familiar knock like a relative would do. I immediately tell them not to knock like that, they are complete strangers. Usually backs them off a bit. I set the mood and let them know I am not interested and say "No" several times.