Nobody likes a bee sting. If you want to counter the effects of one quickly, The Wall Street Journal recommends using a mixture of meat tenderiser and water on the sting.
Speaking with insect sting expert and physician Dr. Theodore Freeman, The Wall Street Journal suggests using the mixture as quickly as possible:
Dr. Freeman recommends applying meat tenderiser mixed with water to make a paste. An enzyme in the seasoning breaks down tissue, and could counteract the toxic proteins in the venom that causes the body to react. Another paste he recommends is bicarb soda and water, which should neutralise the acid in the venom.
It seems simple enough, and will at least make the itching a little less annoying.
What to Do About Bee and Wasp Stings [The Wall Street Journal]