I am trying remove all the unwanted layers from my models and returning after being purged out. These layers are in the imperial.cfg file but even if I remove them there... they always come back.

How do permanently set the layers I want to use?

[Equipment Layers]
Layer1=System 7 Continuous
Layer2=Border 7 Continuous
Layer3=Bom 7 Continuous
Layer4=Cl 6 Center
Layer5=Dim1 1 Continuous
Layer6=Dim2 1 Continuous
Layer7=Equip 120 Continuous
Layer8=Exist 5 Phantom2
Layer9=Graph 6 Continuous
Layer10=Steel 8 Continuous
Layer11=Text 7 Continuous
Layer12=Viewl 2 Continuous
Layer13=Cl_Steel 6 Center
Layer14=HVAC 120 Continuous
Layer15=Cl_HVAC 6 Center
Layer16=TopWorks 3 Continuous
Layer17=Clash 1 Continuous
Layer18=Equip_Insulation 120 Continuous
Layer19=CADWorx1 7 Continuous
Layer20=CADWorx2 7 Continuous

You should be able to open the cfg in a text editor and delete everything after the "=" for layers you don't want.

I think all of those layer indices are mandatory, and are expected by the program. The only way to do a "full purge" is to open the DWG file in a vanilla/non-CADWorx profile.