I still use oil on the plug threads too. Just a little and wipe off any excess. Some states did consider it to be smokeless. Im pretty sure most have changed that ruling now.
My favorite way to clean BH209 fouling is run a dry patch or two first all the way through the bore with the plug removed. That will push out most of it. Then use whatever centerfire solvent you like to actually clean the bore. After its clean run a couple of patches with a synthetic gun oil or CLP.
BH209 fouling is virtually non corrosive but under some conditions such as high humidity it can happen. So if you have more than one tag to fill just run a dry patch to swab most of it out after your first shot of the hunt. That should get you a couple days or more without much risk of any rust.
