how to treat cockroach in TH

need your help:

i got a TH, tenant just moved out left the mess on me. the cockroach running all over from ceiling, from dishwasher, from carpet in all floors. called two professional companies:
one company said using fogger, gaurantee for 30 days, charge $150. after 30 days, another $150. i guess this method just get the cockroach for a vacation in the neighbours.
the other company said treat from back of the walls, but didnot know much details. charge $299.

my questions are how did you treat coackroach in this situation? what is the best way? which company?

thanks a lot.