I need to make a short circuit (don't ask why, long story). There are two 3mm bare wires some 5mm apart elevated some 5mm over a surface. I have limited access to the conductors -- from the top via 2mm hole and through 2mm hole on the surface (which is under the conductors). I have no control over the conductors, it is probably some copper alloy.
My initial idea was to pour conductive powder, but it will not work out, see http://www.experts-exchange.com/Other/Math_Science/Q_28636514.html
for details why. I could find conductive powder (inox or graphite), but the wires are probably oxidised too, so it will not work probably.
Mercury might be a solution -- chances are it will dissolve oxide and make proper short circuit. But it is toxic and also might move away from the conductors from vibration. I was considering warm gallium which might work too, but I am not sure if it will dissolve the oxide layer on conductors. Also it is difficult to clean afterwards.
An ideal solution should be easy to execute and cleanup, cost of materials is less of concern.