What did people sacrifice for hades?

Black animals.

"When the Greeks propitiated Hades, they banged their hands on the ground to be sure he would hear them.[9] Black animals, such as sheep, were sacrificed to him, and the very vehemence of the rejection of human sacrifice expressed in myth suggests an unspoken memory of some distant past.[citation needed] The blood from all chthonic sacrifices including those to propitiate Hades dripped into a pit or cleft in the ground. The person who offered the sacrifice had to avert his face.[10] Every hundred years festivals were held in his honor, called the Secular Games."