The best way to get rid of roaches permanently and fast is to hire an exterminator.
Make sure the house is cleaned up and keep food debris away from counters, floors etc and wash your dishes often.
Then hire an exterminator to come in and have them rid the house of roaches.
However you can also use either ammonia or bleach to spray onto roaches and kill them instantly or use Raid roach killer.
Another option is to place roach motels out and sticky pads to catch the roaches and also fog the house with roach fogger.
Both bleach and ammonia does kill roaches but never mix ammonia with bleach as that creates a deadly gas that can kill you quickly.
If you use ammonia to kill roaches you dilute some ammonia with some water and then spray the roaches directly with the ammonia and the roaches die within seconds.
Bleach also kills roaches when you spray them with bleach and both ammonia and bleach do work equally as good.
Bleach does kill roaches and when you spray the roaches with bleach the bleach kills the roaches within a few seconds of spraying them with the bleach.
If you have a really bad roach infestation it's best to hire an exterminator because roaches are very hard to get rid of fully on your own.
I had a rental house and had to hire an exterminator to come in and kill off all the roaches and it was money spent wisely.
When killing roaches with bleach the bleach kills the roaches within a few seconds of spraying them with the bleach.
You can spray the roaches directly with undiluted bleach and the strong chemical of the bleach will cause the roaches to die within a few seconds.
You can put the bleach in a spray bottle and spray the roaches directly then vacuum up the dead roaches and the bleach also acts as a disinfectant to clean the area where the roaches have been.
Some smells that roaches hate and the smells that will repel roaches are Lavender, Citrus and Eucalyptus.
The roaches hate those smells and will avoid areas where those smells are.
Dawn Dish Soap and even bleach will kill roaches near instantly or get some roach spray and it too will kill roaches and another good way to get rid of roaches is to remove any food, dishes etc and turn off the electricity in your house and use a fog canister for roaches to fog the house and kill all roaches in the house.
If roaches do contaminate your food you need to throw the food out because it can make you sick to eat food that has been contaminated with roaches even when you heat the food up.
When roaches contaminate food the food should really be thrown out and not eaten.
Although heating of the food that the roaches contaminated should kill the germs from the roaches as long as you heat the food hot enough it's still not worth the risk to your health to eat the food that the roaches have been on.
When roaches contaminate food it's best to throw it out.
You could still become sick from eating the food that the roaches contaminated especially if you haven't heated up the food hot enough.
Heating the food up to 400 to 500 degrees or more should kill the germs that the roaches left on the food but still it's not a good idea to eat the roach contaminated food.
There could also be some dead roaches or dead roach eggs in the food even though you may not be able to see the roaches or roach eggs.
If you have a roach infestation I would recommend hiring an exterminator to kill the roaches.