Ironically, Ortho Home Defense is great for most things, BUT one exception is.. you guessed it.. house spiders
Whenever I use it in my basement for example, the ONLY bugs I see for about 6 months are brown house spiders. They seem to go on the hunt for their now dead prey and expose themselves on floor and walls. Easy to swat at that point, but still.
DM earth is microscopic ground up sea shells basically right? So it's good for any soft bodied insect since it's like a barrier of razor wire to them. Literally slashes them to bits when they try to cross it.