Do not nurse this along. It will get worse not better.There are no botches for this sort of thing to make anything like a permanent solution.
You need to ascertain if the problem is the device of the lead/plug. one thing I see often, with laptops and other such devices, is that the socket on the pcb of the device works loose and the solder cracks. In that case, opening it up and touching up the solder with a 25-30watt iron will probably solve it, unless the socket is damaged and needs changing.
If it is the lead/plug, buy a new barrel plug of the same type as the original - see maplin and the like - cut off the old moulded-on plug and cut back the lead a few inches .
Solder on the new plug, making sure the correct wire goes to the right terminal -the tip /core and outer /ring polarity must be correct.
Hope that helps