I've had plenty of door to door people. If it's the neighborhood kids in my mom's neighborhood, I'll tell them when she'll be home because I know she'll buy from them. I've always found that not opening the door but saying I'm an out of town guest is a good plan. "I'm sorry, I'm not actually from here. I'm visiting a friend who rents. No, I don't know the landlord. No, I don't know how you can reach him. No, he doesn't live here. No, my friend has literally no power to make any changes on the property. No, I don't know when my friend will be back."
Most of the salespeople in my area tend to be home repair people, fixing your rooof, or offering lawncare services. Either that or selling magazine sales or something else to help the neighborhood. I'm not sure exactly how that one worked, but he had to get several thousand points and was trying a hard sale on me through the door. He even held up his order form to the window to show how many points my neighbors had given him by buying things. Um, no, dude. I just told you I don't live here, there's no way I'm going to buy something from you when you're holding up a sheet if paper with other people's information on it. Sorry.