The mixture of cum and blood when you fuck a girl on her period.
I made satan's cocktail with my girlfriend last weekend.
The rare term of describing how it feels to temporarily choke on your own spit mid sentence, usually some people use this term in an angry, annoyed way (In an irrational tone of voice)
Random Guy: "Steve, this morning I just got Satan's Mouthwash 3 times!"
Other Random Guy: "That sounds horrible, Alan."
Had the lads over last night, they fed the wife's bedlington terrier 3 bowls of vindaloo, woke up this morning and the kitchen floor is covered with satan's dumplings!