The artifact that Raze was using this time wasn't exactly a magical item, so it wasn't easy for him to see the effects of the chalice or know how to really use it. As a researcher in the magic field, he had his ways, as mages had to learn about enchantments before they could ask them to reveal their information to themselves.
That though was a process that would take some time, and Raze had been focusing on much larger things. Truthfully, he never thought he would be using the chalice so early on, due to the chance of what would appear.
Only when he felt he was strong enough to take on someone from the Divine Realm and reach the Divine stages did he think he would use such a thing, so he never fully went into detail about learning how to activate the chalice.
However, he did remember the details that had occurred in the Lethal Bite Clan, and how a mage from back then was used as well.