Spider-killing sprays also kill flies, but fly-killing sprays don't kill spiders.
Spider-killing sprays also kill flies, but fly-killing sprays don't kill spiders.
They're the same price at Walmart, so it pretty much always makes sense to go with the spider-spray.
The flies don't die 'on-contact' like they do with the fly-specific spray, but they do die after a brief period of delirium.
At least where I live, it doesn't make sense to kill spiders at all. There literally is not a single local spider species that you might encounter at home that's even somewhat dangerous (AFAIK even in the wild there's only one, and even that one usually won't kill you). If there's something that's too gross for you, just pick it up with a glass and throw it out of the window (which is much easier with spiders than with flies). Spiders do kill flies and other critters that are annoying or even dangerous, so you definitely want the poison that kills flies but not spiders.
We have black widows, brown recluse, and wolf spiders, but bites are extremely uncommon and actually less dangerous than advertised. Yes, you should see a doctor right away for at least the first two, but it's not worth killing all the house spiders to avoid them.
Not sure what wolf spiders are doing on that list, they are totally harmless. Also everyone (except people in Antartica) has wolf spiders.
Black widows and brown recluses are medically significant but haven't killed anyone in the US in decades. But do go and see a doctor if you get bitten.
Also check this map to make sure you actually have brown recluses where you live. A lot of spiders are mistaken for them.