Rooms full of weird pools meant to tempt, trap, lure, and reward adventurers go all the way back to those halcyon days of B-effing-1, In Search of the Unknown. That was back when TSR didn't sell adventurers to follow, they sold modules to explore and use to create your own adventures. One of my earliest memories as a player was a fight against kobolds where my cleric used a sling, and my older brother (the DM) had to explain that a sling was not a slingshot. My second oldest memory is poking around the pool room in B1, finding one pool with just sand in it, and finding one full of healing potions. That's about it.
Magic pools are a must-have in any mad wizard's dungeon, and Castle Meatgrinder is no exception. One black ichor, one purple magic, one green slime, and one cool refreshing water pool.