Luis Suarez successfully used this in the 2010 World Cup quarter-finals in the Uruguay vs Ghana game: https://www.youtube.com/watch?v=dM-29hy-Qyw - Ghana missed the penalty, which led to a penalty shootout, which Uruguay won.
Skimming through the laws of the game (https://downloads.theifab.com/downloads/laws-of-the-game-202...) I do wonder whether a trainer and up to 4 other players (because a team which can field less than 7 players forfeits the game) climbing on the crossbar until it breaks could be advantageous in some situation as well since
> If it cannot be repaired the match must be abandoned.
Very unsportsmanlike indeed.