I honestly neevr thought about putting a "No Soliciting" sign on our home. Our Bosco sounds alot like your Trucker, we have a glass door so he also goes into kujo mode when someone approaches. He will dart to the door and slam his front paws on the door and hit it over and over until we get there. It's really scary :( He scares the crap out of anyone who comes ringing our doorbell.
They back up at least 10 feet from the door until we get there.
Were working with him, but it never seems to be getting any better. Time will tell
I feel for you