2 days before I saw this thread, my 15 year old son came to me and said 'Hey dad, watch this';
He then took a homemade tool made from the tin from a soda can, and easily opened a combination lock.
He took the tin and shaped it into 3/4 of a cylinder, about 1/2" long, with two flaps for handles. He wrapped it around the part of the u-shaft on the end that engages the locking mechanism.
Slide it down inside, and simply rotate it, and the lock opens instantly.