a) Change your name. Something like Wellard Pit-Bull is far less inviting than "Sweetheart".
b) Learn one or two stock phrases, or simply make some up, in some foreign language. Just keep repeating these phrases whatever the salesman says. Just make them louder with each repetition, and maybe start waving your arms about.
Making up your own phrases has the additional benefit that there's no chance of the salesman understanding what you're saying and making replies that you won't understand
c) Start telling him about the snails in your bath.
michael adams