First order bentonite if you don't have any. It's a dehydrated cosmetic clay that comes as a powder. For this recipe, the fineness of the powder doesn't matter. Here's a link to one I use: http://www.amazon.com/gp/product/B0064O9C3C/ref=oh_details_o04_s00_i04?ie=UTF8&psc=1
Step 2: Plantain
Gather plantain leaves. Plantain is a weed as common as dandelions. Gather only the leaves from a yard that has not been sprayed with herbicides, pesticides, or non-organic fertilizer. Collect enough to fill your dehydrator, or enough for two cookie sheets. Rinse it off and dry it in a salad spinner or use paper towels. Dry it totally in your dehydrator or in your oven on it's lowest setting on parchment-lined cookie sheets. It's done when it's crispy.
Step 3: Put it all together
Grind up the dried plantain leaves - a coffee grinder is great for this, but use what you have. Combine equal amounts, by volume, of bentonite and plantain powder. Mix it all up and keep it in a handy, air-tight container (I just use a Ziploc baggie, but you can use whatever you like). It should keep forever, approximately.
Step 4: Use it on a sting
When you get a sting, a mosquito bite, or run afoul of stinging nettle, just put a quarter teaspoon or so in the palm of your hand, add water to make a mud that is pretty damp, but not runny. Apply the mud to your sting and leave it to dry. As the mud dries, the poisons are drawn out of the sting. Once the mud is dry, just wash it off. You may find that you need to repeat this process after an hour or so, but for most stings this remedy works in one application.