The sticky red goop is a quest item used in The Fremennik Trials quest during Peer the Seer's part of the quest.
It is made by heating a red herring found upstairs in his house, and is then used on a wooden disk also found there to turn it into a red disk. The red disk is used on an abstract mural downstairs along with another old red disk in order to obtain a vase lid needed to complete Peer's challenge.
