I hate chiggers!!! Now that I got that out of the way, I found some interesting info on Missouri Conservation Dept. website.
"By far, the most effective and time proven repellent for chiggers is sulphur. Chiggers hate sulphur and definitely avoid it. Powdered sulphur, called sublimed sulphur or flowers of sulfur, is available through most pharmacies. Dust the powdered sulphur around the opening of your pants, socks and boots. If you plan to venture into a heavily infested area, powdered sulphur can be rubbed over the skin on your legs, arms and waist. Some people rub on a mixture of half talcum powder and half sulphur.
But a word of warning: sulphur has a strong odor. The combination of sulfur and sweat will make you unpleasant company for anyone who has not had the same treatment. Sulphur is also irritating to the skin of some people. If you have not used sulphur before, try it on a small area of your skin first.
The best precaution against chigger bites is simply taking a warm soapy bath with plenty of scrubbing as soon as possible after exposure. If you bathe at once, while the chiggers are still running over your body, you can wash them off before they bite. A bath will also remove any attached and feeding chiggers before you start to feel the itch.
Warm soapy water is all that is necessary to remove and kill chiggers. There is no need, and it is rather dangerous, to apply household products such as kerosene, turpentine, ammonia, alcohol, gasoline, salt or dry cleaning fluid. Don't do it.
Attached chiggers are removed by even the lightest rubbing. If you are away from civilization, you can remove attached chiggers before they do much damage by frequently rubbing down with a towel or a cloth.
What can you do to alleviate suffering if these precautions fail? Lotions will relive the itching somewhat, but no substance is completely effective. The only ultimate cure is time, since there is nothing you can do to dislodge the chigger's feeding tube, the true cause of your itch. You must simply wait until your body breaks down and absorbs the foreign object.
In the meantime, local anesthetics such as benzocaine, camphor-phenol and ammonium hydroxide may provide you with several hours of comfort at a stretch. Over-the-counter creams can also help. In rare cases, some people are allergic to chigger bites and require prescription medications from their doctor.
The most popular home remedy for which there is little justification is to dab nail polish on the welt. This cannot "smother" the chigger because it has not burrowed into your skin, and it was probably scratched off long ago. The only benefit to applying a thick coat of nail polish is that it helps to remind you not to scratch the bite.
Chronic scratching will only cause the stylostome to further irritate. Scratching deep enough to remove the stylostome will probably cause a secondary infection that is worse than the original chigger bite. If you do scratch, disinfect the chigger bite with topical antiseptics."