For normal races, if you have a normal chunk (small snake), and a contaminated chunk (cockroach) and try to eat when hungry, you'll be prompted to eat the safe chunk.
For hill orcs, if you have a normal clean chunk, and a rotten chunk, it won't go first to the clean non-rotten chunk, which is the preferable chunk since it cannot make you ill.
I would actually prefer to try the rotten chunk first, because it may rot away completely before I need to eat again, while the clean chunk is less likely to do so.
Would be preferable as an option in the rc file, I eat rotten chunks like all you can eat buffet with sap+ races. -PV