The loser endorses 50 real connections for wildly unrelated skills, falconry, cold fusion, puppetry, from their real professional account in one sitting. The notifications do the punishing. Follow-up questions from recruiters must be answered honestly.
Budget note: this one costs nothing but dignity, which makes it a strong pick for leagues that would rather spend the pot on the champion than on the loser's downfall.
Seen in the wild: fantasypunishments.com