"Wash out your mouth ...Scourgify!"
-- James Potter to Severus Snape (OP28)
Cleans things with pink frothy soap bubbles.
Wand movement: a smooth, sinuous motion, like a letter ‘S’ (BOS3)
References from the canon
- Tonks used "Scourgify" to clean out Hedwig's cage in Harry's bedroom (OP3).
- James Potter used "Scourgify" to "wash out" Snape's mouth when the latter called Lily a Mudblood just after their Defence Against the Dark Arts O.W.L. (OP28).
- Hermione taught Neville a Scouring Charm to clean frog guts out from under his fingernails (GF14).
- A Scouring Charm is required to eradicate an infestation of bundimuns (FB)
"excoriata" L. to be stripped of' (thanks to Ruth Eyres); also Old French escorgier - "to whip"
The term "scourge" has been used in history to mean something violent. Attila the Hun was known as the "Scourge of God" when he invaded Europe, and before that the Roman Legions used leather whips known as scourges. Roman soldiers first scourged Jesus before they crucified him. See more: Wikipedia: "Scourge"
So J.K. Rowling is using an interesting combination of "scourge" and the suffix "ify" in "Scourgify" as the spell used when James Potter washes out the mouth of Severus Snape just before hanging him upside down, basically giving him a whipping in front of the whole class as well as Lily Evans. While earlier in the book Scourgify is a simple cleaning spell for an owl cage, in the context of "Snape's Worst Memory" it was misused in a violent way and the context of bullying. (OP28) Also just as interesting is the way the wand motion for the spell is to form an "S," not just the first letter of Scourgify, but a symbol of Slytherin House, and the initials of Severus Snape, yet the spell is cast by a Gryffindor. (BoS3)