This soap is a lethal weapon used by the Villain League via Dr. Facilier.
The soap is made of regular soap, bubble solution, plant sap, and champagne. The plant sap must be extracted from tobacco plants and added to the soap, champagne, and bubble solution. These 4 substances would be combined by Facilier's voodoo magic, and turned into a regular soap bar.
The soap is a lethal weapon and is mostly used as a trap. The soap cannot be consumed, but it can be rubbed on like regular soap, or it can be used in a bubble wand. When this happens, the victim will experience Pink Elephant Fever. This fever causes the victim to see the dreaded Pink Elephants and gets knocked out in the process.
The soap was only used in SpongeBob and Friends and Alice in Wonderland. The soap was used as a means of knocking the Lodgers out so that the League could get to Alice.