Wikia

The Kotochul Egg is a rare egg which can be used in an Empath blocking potion to prevent someone with the power of Empathy to know what you are feeling. The only known location of this egg is in Swamp Lands, and is hard to find. ("Love's a Witch")

Chris Halliwell tracked down a Potion Sorcerer who would help to create the potion for him so that he could continue what he needed to do in the past without the interference of his aunts or parents.