Furutech Nano Liquid
Furutech Nano Silver Gold Liquid is a nano particle suspension of silver and gold in a squalene oil. When brushed on to an audio signal or power conductor, the tiny particles of gold and silver, no larger than 8 nanometers (millionths of a meter) flow into surface deformaties and cracks. This improves conductivity, reduces noise, and the oil helps protect the conductors from oxidization.
More information on Furutech's website
$180 for a 2ml bottle