I get a pretty bad reaction to stings so I use ketchup. It works better than anything I've ever tried. I keep packets in my FAK and in my glove box. The older it is the better it works. I think the acid neutralizes the poison. Within about a half hour to 45 minutes you cant even tell I was stung. Without it, my eyes swell shut. I also keep benadryl with me and if I'm stung more than once I take that too.