re: Submerged shotgun

It's REALLY good and not expensive. 10 bucks a can and you can do several guns with one can. It WILL take off the oil/gunk. It vaporizes after use so it is vital that you hold your firearm part at an angle so the carbon can drain out of it while the scrubber is still wet.

Here's a link with product info and a few reviews.
[link=( https://www.midwayusa.com/product/382417/birchwood-casey-gun-scrubber-synthetic-safe-cleaner-13-oz-aerosol)] Gun Scrubber[/link]