Tobacco poultice for stings and bites: Since childhood (over 50 years), I have been using pure tobacco for drawing the poison out of a bee sting or a spider bite. Simply wet the tobacco with water or better yet saliva (it is acidic and helps break down the tobacco and get things happening quicker) and tape it with a bandaid or tape onto the wound. Leave it on for a couple of hours and put on a fresh application.
You have no healing remedies for spider bites. I was recently bitten by a brown recluse spider and made a tabacco poltis using 2 cigarettes and enought water to moisten. Heated it in the mircowave, covered the bite with it then put plastic over it and went to bed. The next day a huge blister had formed. I then punctured it and removed alot of fluid which had some of the venom in it and repeated the next night. Really lessoned the effect of the bite, which can be life threatening. Also works for bee stings.