I think that the best way to kill G0-T0 is to exhaust his powerbase and draw him out. As Warren said, finding G0-T0 is like finding a needle in a haystack.
Personally, I don't see how effective sitting on Malachor is going to be for Traya. Really, G0-T0 could just drop in a few droids and figure out a way to reactivate the Mass Shadow Generator. Traya's best option is to leave Malachor and either set up somewhere else or sit in one of her ships. Either that or find a way to permanently remove the MSG from the equation. I don't know how she could do that, but doing so would greatly increase her chances.
Either option would give her the ability to send her assassins to infiltrate Nar Shaddaa and gather intelligence for her.