The magnet is an electromagnet so when current is applied it de-magnetizes for a split second to release the bar when then causes the shutter to function.
If the magnet is not releasing then the fire wires of the windings have become damaged as power is in unable to pass though it. Check to see if you damaged or dislodged something when you cleaned. If you don't see anything its time to break it into a camera repair person as you do need some specialized tools to test and repair the control circuitry as well as gain access to the needed parts.