The cauldron allows you to make one weapon stronger every 6 hours (or 1 hour if you are in a hurry). HOWEVER, and this is cheap, I found on my samsung tab that by minimizing my game after making my weapon stronger, I could advance the internal clock on my tablet six hours, maximize the game and reuse the cauldrom right away. Minimize, minus the clock six hours (or 1 if you want), maximize and repeat to continue to strengthen your weapons.
Do you guys get it? If not, I will try to explain again/add pics. It is cheap and I only tried a few times, but it can be done, by playing with your tablets clock.