Have you tried diatomaceous earth food grade I sprinkled it all over my bed and sheets and pillows and everything and on the floor because I have dust and I think that they live there too. I did my son's bed also he is 11 tho. I bought mine at this site http://freshwaterorganics.com/.
It is cheap and it works so far soo good I even bring it when I stay at other ppls houses, hahahah. It has many uses this is just one.