I was solicited by a very nice, young articulate woman who provided me with a convincing demo of Extreme Kleen concentrate - selling for $87/gal.
The product worked very well from the spray bottle she used, and I was convinced to purchase (and sign for) 1/2 gal for $47, and that she would be back later with the product and to collect her $50 (with tax, even though PA sales tax is 6% and it should have been $49.82 - only an 18 cent ripoff, but nonetheless incorrect, so I doubt the PA State gov would receive any of the tax collected).
After she left to finish her run in the neighborhood (she showed me checks from neighbors who bought the product) I got my laptop to check out Xtreme Kleen and see if was making a mistake. I found ripoff reports from several states regarding door-to-door sales of this product.
I then checked with my local police to see if she had a permit to conduct sales in my area. They said no one had issued any recent sales permits for my area and that they would send an officer to check this out. When she returned with her boss, I questioned her as to the contents of the bottle I was to receive and was told she would mix it right there in front of me and demo it in my house if I liked. That negated the tales I read of not getting what you pay for, but I was still leery of buying something brought to my doorstep that I hadn't solicited myself. So I passed in favor of more research into an equal, lower priced cleaner.
The police showed up about 5 minutes after they sped away (following my informing them that I had checked with the police as to their legality to be soliciting in the area). I failed to get the plate # so I described the van and them. He left to seek them out but returned later telling me that they must be long gone.