There are 47 nations sitting on the Council, and membership rotates (every year a third is replaced). The membership of the organization reflects and basically is proportional to membership in the UN. You have Sudan and China on HRC as you have these and other miserable countries in the UN. The stupid reason you give for non-cooperation also works for non-cooperation with the UN. Why not suggest that Israel pull out? Perahps you should pull out of the human race because there are idiots included? The way one should work with a Commission of Inquiry is to look at its composition and see if there is reason to worry. Even stupid people can appoint reasonable people to represent them. This is the way you get represented by Knesset members..
Israeli soldier lightly wounded after being hit by car south of Hebron (Haaretz)
from the article: J Street keeps accumulating scandals