Although it is counter intuitive, best thing is to not move/swat at them- they are somewhat attracted to movement. I once got into a small red wasp nest (15 wasps) along the edge of a field while mowing hay- although I was very alarmed, I saw the wasps going for the moving fan and they seemed to also be attracted to the exhaust stack. I stayed perfectly still and didn't attract their attention and they all gave up by the time I got 200 feet away. I braved another round with the same strategy and it worked again.
As a bee keeper, once bees start to attack/sting they release alarm pheromones and draw more bees to the area that is being stung. Once the bees are alarmed, there is isn't much you can do to stop them- I had a really mean hive and once they got after me (I was wearing a suit, but 1-2% of the stingers can go most of the way though the suit/leather gloves- so when you are getting attacked by 600 bees, you can expect 6-10 light stings+ the ones that crawl up your shoes and sting you through the socks...)- even smoking myself with heavy puffs of smoke from my smoker (making a smoke cloud around myself) didn't seem to deter them. I suppose the bug killer would kill a few thousand, but there would be several more thousand on the way, maybe the fire extinguisher would work better than nothing at all.
I am not familiar with africanized bees, but I have found that the best thing to do with my angry bees is to get away from the hive as fast as you safely can (put the tractor in road gear if you can travel away that fast safely). I have a golf cart and it is really handy for a quick retreat. Most of them give up after getting 100 yards from the hive but a few will hang on for 200+ yards.
Running into a garage or enclosed building or even a house and closing the door is a good strategy if you are on foot. In my experience, once you get indoors, most of the bees that followed you in will immediately give up and fly back to a window and try to get out. I harvest honey inside my garage (doors closed). A few angry bees always follow me in, but as soon as I get into the garage and the door is closed, they would instantly forget about me and fly to the windows and try to get back out. Running under a low shade tree doesn't have the same effect (been there, tried that).
