The remnants of the Guru, the water, food, and other items offered to Shiva, are considered acceptable and fit for consumption by the disciples and devotees of Shiva.
A rite performed without hindrances in the middle can be fruitful. The subsidiary rites shall also be performed. Hence at the beginning of sacred rites, an intelligent man shall adore Gaṇeśa.
An intelligent man must worship all deities in order to ward off all sorts of hindrances. (There are three types of hindrances. The first one, the Ādhyātmika hindrance is the ailment of the body, whether it is a fever or a tremor or other type of sickness.