When I was growing up in Florida many years ago, my dad believed that 'conventional wisdom' offered two ways to keep cockroaches out of the house:

1. pile up banana leaves around the foundation.

2. sprinkle a couple hundred pounds of the dust left over from the coffee roasting/grinding process in the crawl space under the house.

The former didn't work, and while the latter smelled fabulous, it really didn't work either.

My mom finally observed that the thing that you really had to be concerned about was the size of the cockroaches. If there were big, that meant that they were adults. Since there was no practical way to keep them out of the house, just step on them, wipe up the mess, and go on with life.

But if they were small, that meant they were breeding in the house and action was required. Unfortunately, there wasn't a very good way to prevent that either. So step on them, wipe up the mess, and go on with life.

So that's one of the reasons I don't live in Florida.