Your home base says Utah but I don't know if that is where you actually are staying. Since you mention nasty neighbor, I assume you are talking small german cockroaches... the typical nasty-neighbor companion. This question might get different answers based on your location and the type of roach. We had some big issues in FL once right after a storm went through. My wife freaked the heck out. Those were giant American roaches but this still worked..
As a general rule. Exterminators would be acting out of there own best interest to do anything but spray a little over diluted, mild pesticide to get them to hide from you a little while until your check clears the bank ...and then return.
It may be difficult to find but you want a product called Demon XL. It comes in a foil pack that contains 4 small dissolvable plastic packs. You drop a plastic pack into a garden pump sprayer with a gallon of water inside. Shake, pump, and low-pressure spray it in the corners, crevices, under cabs, etc. Stay AWAY from your pets food dishes, bedding etc. ...Your own as well. Use common sense when spraying it. This is a very toxic poison. You don't need much.. especially in an RV.. it is very very effective in small quatity. It can also be sprayed around your drain hose, tires, and to create a temporary perimeter around your unit. It's available online still I think, and also at some agricultural suppliers. I have bought it at ag supliers in FL, VA, NC, and PA.
Use with care, You may be bending some agricultural rules depending on your locaton and use but you wont have roaches any more.
