It would depend on the source material and how much 'noise' there really is. Sometimes the noise is never noticeable when mixed with the audio, but it pops out during quiet parts.
If its only really noticeable when quiet... I would try to cheat it first with a gate with a lookahead(like the sonitus one has I believe in sonar). Put it first in the chain and adjust the gate so that it doesnt eliminate any audio, but promptly closes when the instrument sound goes away... effectively eliminating line noise during the 'silence". That lookahead will keep the gate opening sounding natural.....allowing it to open just before the wave starts(so its not unnatural sounding because it pops in from a fast attack....and/or cutting off too much transient because you've set a slow attack to keep the popping out).
That alone might do the trick. If you struggle to get a gate setting that works naturally, you could spend a little more time doing the same thing with track volume envelopes.
Another thing to try is a noise reducer plugin. Plop it right on the track that is the problem and let it study and learn the noise profile during periods of silence. The suck the noise out of the whole track. Careful though. this can be destructive to audio and actually hurt your sound. Its basically a try it and see if it works kinda thing.
If the noise is simply too obvious and you cant reduce it without somehow hurting the audio... I would let them know and see what they have to say