One of them can sacrifice an additional part into the scrying bowl to get another use from it. This will intensify the effect the person has already received.

They can also give the scrying bowl to another character if they don't want to worsen their own effects. Anyone who wants to use it must offer a flesh sacrifice, though they don't need to harvest it themselves. Wanda and Michael are welcome to provide a pre-harvested appendage. The individual will receive the same choices described previously.