Lavender oil, (and a little tea tree if ur feeling fancy) drop some oil in a spray bottle with water. I love the shit so I dump the oil in there but a table spoon will do. Also useful for ticks on hikes around your ankles. Note some species dgaf.

Remove the food source and the spiders will go. They frequent certain places because the hunting is good.

Nothing you can buy in a store is natural. You can get things that will deter/kill insects that aren't toxic to humans, like peppermint extract, but I don't think calling something that humans pressed and processed from a plant that was grown, cultivated, and bred by humans "natural" makes any sense. Most plants produce their own insecticides, so make a list of your favorite herb/flower scents, check which ones work/are available, and go to town.