I think that, given the pros and cons of using insecticides on my skin, or adjacent to it, I would opt to either: (A) use a natural - perhaps homemade repellent - that can be sprayed on my things, (B) Bathe in scented soaps that have a scent the bedbugs are known not to lime - lavender for example, and/OR (C) take antihistamines and tough it out.
While I have not been bothered in six Caminos since 2013, I realize there is always a first time. During the interregnum caused by my being a caregiver for my critically ill wife, I have been doing research on concentrated solutions I can make at home, carry on the plane in a 3 oz / 100 ml or less bottle, and then dilute using commonly available rubbing alcohol, in a small sprayer bottle on arrival in Spain, France or Portugal.
This seems to be a valid approach. Pre-treat my sleeping bag, and if staying in a hostal that supplies bedding, spray the sheets blankets, etc. before I plan to turn in for the night.
Just thinking out loud.
Tom