I wanted to post some thoughts on Soundsoap 4 so here are some.  Its a very simple interface very clean and efficient.  What is outstanding about it is it works. I had Soundsoap 1 when it first came out and I used for many things. Over the years I let it go. I didn't upgrade because I was a bit peeved when they came out with Soundsoap Pro a long time ago and were asking more for the upgrade than what I paid for the original. Plus they had a bad way of authorizing it. That is no longer the case and it is like the original except much better.  
 
For the price I think its a good plugin for reducing most noise without destroying the music in the process. It is a CPU hog but that is because it has hard core processing going on that does the job. 
 
I would give it a try with the demo and see if it will do what you wish it to do. Because its an old friend to me I am happy to have it running again. 
 
You can check it out here http://www.soundness-llc.com/products/soundsoap4/

Yet another option is the Magix stuff: http://www.magix.com/us/audio-cleaning-lab/
I don't own these but have used their other stuff which has some of these features and someone here (forgot who) recommended it before.
 
Or, maybe you can loop back the digital io on the scarlett with RX..