What Would you do in a Situation Like That?

Yesterday, I was home alone for a few hours.  There was a knock at the door, but I wasn't expecting anybody.  I opened the door to find two men in camoflauge outfits talking rapidly in Spanish.  I stopped them and said my typical,

"no hablo mucho espanol."  (I don't speak much Spanish.)

Which led them to continue talking about something I didn't understand about my "pila" and they held up small packets of powder and kept saying they wanted to come in.  Well heck no, I wasn't going to let them in!  I said, "esta jabon...se vende"? (is that soap...for sale?) and they laughed and said blah blah blah and so I said, "no quiero, ya lo tengo". (I don't want, I already have it.)  They laughed at me and kept insisting that I let them in.  So I said, "mi amiga habla espanol y regresa a las cinco" (my friend speaks Spanish and she'll be home at 5.) 

I told Bridget about it and how the way they laughed at me and their insistence that I let them in, and their confusion when I wouldn't let them in made me think that they were legitimate and probably not soap salesmen.  It turns out they wanted to put powder in our "pila" (standing water and plants and storage tanks) to help contain the recent Dengue outbreak, and I probably could have safely let them in.  Then she said it is good I don't let strange people in the house, even if all they really wanted was to save us from Dengue.

"Ya lo tengo" is right.  I already have it.