I have a serious cockroach problem?

you need to bomb both apartments at the same time put two different bombs in each room open cabinets etc put the bombs in every room attic to basment the reason for two diffrent ones is if one type doesnt kill tthe other will I had done this in my home 20 years ago when my nephew rented and brought a stove with him froma restaurant that had the bugs we also had big water bugs knock on wood we have,nt had a roach since if the other tennants don not do this then you will still have the pest.Anextermanator will water down the chemical after awhile he will keep comming.If they dont comply call the board of heath on the landlord.