I need to bomb the garage for spiders creepy crawlies so that we can empty it out without fear of redbacks, whitetails or huntsman.

I have two raid bombs which is enough to do the garage (6mx6)

But my problem is the internal door from the garage to the house.
It has a weather seal on the bottom and I'm surface spraying all around it but I have images of spiders xrawling thru horror-movie style as soon as the bombs start to work.
That and whether the fumes can get in and would cause a problem

Has anyone used these before?
Any suggestions?