Not on a C130, there's no room. The last time I flew on one was during the PGW. The crew chief had rigged up a toilet. It was a toilet seat strapped to a garbage can and lashed to the side of the aircraft. He also had a shower curtain that the person could pull around themselves for privacy. But because of the way the cargo hold was configured, the shower curtain only covered from the neck down when sitting. So any female who used this makeshift toilet whould have her head sticking up out of the shower curtain when she was sitting down!
Makes me thankful I took Delta took go to GWI (seriously, we had flight attendants and everything).