Looks like the guiding is working a treat Scott
Great to see another ist user doing deep sky
Scott to neutralize the background on Eta. Before doing any processing on the sub - go into the Levels palette and click on the centre grey eyedropper at the bottom then place the eyedropper on a corner of clear dark sky in the image - click - and levels will adjust to a neutral colour background - then click OK.
Having said that I have found it sometimes doesn't work well on every image. But give it a try anyway!
Barb