I would never use pesticide in a small livable space like a camper. There are enough chemical villians everywhere in food water and air. Go ahead with the experts ..... I'll stay with a light spray of antifreeze or wd 40. Furthermore termites like wood that starts breaking down from the micro organisms that can live in moisture conditions. Antifreeze will stop the wood breaking down. Rot. and kill the termites. Antifreeze is a good wood rot arrestor because it is compatible with moisture and kills living things. I did not go to exterminator school.
If worried about WD fumes or antifreeze fumes/ vapors then use a high concentration of water and dishsoap. Dishsoap kills most bugs but, Chevron doesn't want to tell you that. Neither does an exterminator.