The cauldrons are warp points to get around the lair faster. You must find both to use the warp point. The locations are as follows:
In pipe near treasure trove cove/clankers cavern intersection(lower pipe) =======> Click clock wood entrance hidden in grass
To left after going up hill near grunty's picture at the beginning and through note door ====> FP, Grunty's Mouth Intersection( You need to shoot eggs to open up this section where the pot is)
In the grunty's mouth/ FP intersection it is up the hill past the 450 note door(you need to poop eggs in the web) ====> Rusty Bucket Bay Entrance
Beginning of Grnuty's Furnace Fun =====> Final Battle