I go with Bullfrog. It was developed by the military for their firearms. They have several products. They have a rusthunter that comes in a spray can like rem oil and break free and it works pretty well for taking off rust and keeping it off. Also they have a rustblocker that comes in a spray bottle. It basically does what sheath does where it puts a little coat over the gun and prevents the elements from getting to the gun. It has a little tacky feel to it but does the job. I hunt on the coast so you need something extra to help fend off the elements. Bullfrog and Breakfree are my #1. Ive used rem oil but it doesnt do the job as well as the others. Just stay away from WD-40.
The ducks are right there. Where? Right there. Where? OHHHH they're right there.
I think the ducks will be better off flying straight.