If you're getting "idling" hiss, noise with the guitar unplugged, about all you can do is gate or noise suppress the track.
If you have a guitar that is noisy you might look at cables, pickups, guitar shielding and the actual orientation of the guitar in the room. Sometimes if you turn a few degrees the noise will decrease.
Overall, it's pretty typical to gate a gained out channel as even the best overdrive/distortion circuit is going to accentuate any noise at input. I used to record with a lot more gain back when I still had hair and would put 2 Boss noise suppressors in circuit: before the preamp and after. The main advantage was that you could run lower thresholds with both.
