Contact form words the public can't use filter

I’m creating a contact form and I get asked the same questions over and over. I made a field that stated I read the disclaimer, I made it very clear that I do not offer “tours” on a particular historic building. However, certain people still can’t read and I still get asked the same questions constantly. Is there a way I can add a filter in the “Message” area that will eliminate certain words someone uses when sending me a message?

  • Tours

  • Visit

  • Visits

  • Visiting

  • Like to see
    Etc.

I wouldn’t even mind when the sender hits “submit” he/she receives a pop-up stating that the email was rejected and I don’t offer tours.