PB Blaster is awesome. Not just on seized bolts, rust prevention, etc., but on killing spiders. When I picked up my Land Rover project vehicle, I apparently also picked up a black widow and some other nasties (it had been sitting in a field for a loooong time). Anyways, by the time I saw the thing, grabbed something to hit it with, it had run off. I sprayed the entire area around where I saw it with PB Blaster. Also took a look around the truck and sprayed all the webs I found with PB Blaster. By that night, there were a couple of non-black widow spiders keeled over dead on the hood--they must have crawled out to get away from the Blaster and croaked. About a week later I found the black widow laying between the rear crossmember and the truck bed. I fished it out and it looked mumified, like the PB Blaster had somehow sucked all the juice/guts/whatever out of it. Very strange looking, but a dead spider is a good spider, so I'm sold.