how to kill chiggers, avoid bed buggs

I have been in U.S for more than 10 years. My career and family are finally doing well, it is time to help others that I always wanted.
The most suffering physically is from chiggers. It is horribly itchy, but cannot see them with your eyes. I googled the syptom and verified with magnifier that it is chigger, tiny tiny creature that bites. I tried many methods:
 1. take bath often, but they stick with clothes.
 2. put the clothes in freezer, that did not kill them.
 3. iron the clothes, still they remain.
 4. wash clothes with heavy bleach, still they remain.
 5. nail polish, not very effective. 
Finally, after years of thinking and testing, I solved the problem:
I bought scotch lint roller (https://sites.google.com/site/fzhangj2ee/kill-chiggers). whenever there is a itch, I roll over with the scotch lint roller, and the chigger will be removed because the lint roller is very sticky. I also roller over the clothes that causes the itchiness. 
 
I also had bad experience with bed bugs, they once hided in a apartment I lived. I did not find a way to kill them, but I figured out how to avoid them:
1. check the bed completely that they do not exist in your mattress.
2. put the 4 legs of your bed, if no legs try to make it happen, in 4 container that filled with oil, so that there is no way for bed bugs to get into your bed without going through the oil.