Hire a professional pest management company to eradicate the cockroach problem.

All he had to do was agree to use them for 36 months on all his jobs (Coke, Diet Coke and Sprite).

You had a water leak, and removed the materials but from the sound of this, you have a mold/mildew problem, and need to address this before sale.Otherwise you knowingly passed on a problem.This must be eradicated or you may well have a legal issue on your hands as well.

Bed bugs are remarkably resilient and a standard winter would probably not be enough to eradicate the problem in my opinion.  

Waited a few months, no roaches, and I didn't call them back.Bottom line, roach eradication is a long grind, not a quick shock and awe treatment.

Trust me, the hotel industry is watching and formulating ways to eradicate STR's and BnB's from their areas.

Think of it as a obese person telling you about a new diet or work out program they are going to start "next week".

This is a flushing agent that causes the roaches to flush from their hiding places, run into the freshly sprayed chemical (I always prefered the chemical Demand CS with an active ingredient of Lambda-Cyhalothrin)It may take 2 or even 3 treatments to eradicate the problem and is not cheap if done right.

There is a company that will come out and totally eradicate the bedbug problem.

I have found out that paying a full-service rental management company can certainly provide peace of mind and a totally "hands-off" experience for out of town owners, but the 20% to 30% of gross rental income fees pretty much eradicate any potential profits you hope to make.