I put white vinegar in sprayer and sprayed the area several times.

We have had to do substantial gutting of the property, spray every surface with bleach, and leave the windows opened for months to remove the smell.  

If they are paying on time spray one time and let them know all the cockroaches are dead or gone and if they comeback the next spray is on you.

Try opening the windows for a little while, running an ozone generator, or spraying lysol air sanitizer.

If not, have insulation contractor spray several inches of cellulose. 2) be sure the duct work is not leaking air.

., I would have served the tenant with a Cure or Quit notice - they painted the condo, which they weren't allowed to do and never asked, installed a kitchen backsplash that had to be pulled off the sheetrock, they stained the kitchen cabinets, they spray painted something on the patio and left a red paint outline, etc.

There is this material we bought at Grainger (https://www.grainger.com/produ...) and then used this adhesive spray to line the ducts near each exchange (https://www.homedepot.com/p/3M...) 

She wrote on the wall herself and spray painted over it. 

For sealing in stains like that (if is from smoking), use spray paint and then normal paint over top. 

A cheap solution would be to buy some bed bug spray from the hardware store.