Homeopathic escalation of priority (It will work if you believe it):
Let's say you're at the ACM international programming contest, and you forgot how to write an efficient factorization algorithm, so the best thing you can do to crack the code is to brute force search the solution, so to make it fast enough and earn the flag, you include the following instructions to the jury:
user@machine: /home/user$ ln -s /dev/null dilute
user@machine: /home/user$ renice +1 999 2> shake;
user@machine: /home/user$ mv shake dilute
user@machine: /home/user$ rm dilute
If it didn't work, is because you didn't mean to believe it.