How did Vijay Singh use the egg? How did he use the lump of salt?

Vijay Singh used the egg and the salt lump to give the ghost an illusion that he was very strong. He used the egg’s cracking sound to show that he could easily break a rock with his bare hands while the ghost has failed to do so.

Vijay Singh later used the salt lump to misguide the ghost that he had the ability to crush rock into powder. This panicked the ghost by a great measure.