Found this on the Web:
Kimchis’ sons did not necessarily die in the role of cohen gadol. The gemara in Yoma describes how on two occasions her son the cohen gadol Yishmael ben kimchis was in the “shuk” on Yom Kippur “between avodas” to meet an “Arab king” and the king’s saliva hit him, rendering Y ben K tamei and unfit to finish the avoda of the day. On each occasion a different brother stepped in for him to finish up as cohen gadol. Possibly something similar happened with the other four.
Per the magid shiur where we are learning Yoma (I won’t name him as I did not ask his permission), Kimchis is described in the Yerushalmi as being like soles (fine flour) compared to other women, i.e., particularly tzanua, thus the name Kimchis (from kemach, or flour). Our rav pointed out that the sota brings kemach (flour) of barley, the only”kemach” brought as an offering, and it is an inferior sort of flour, reflecting the sota’s status. All other flour offerings are based on the finer wheat-based soles. Kimchis, being compared to soles is a kind of antidote for the sota.