This thread is getting interesting and thank you all for the information.

I'll get my little gun out later and see if the cotton mop is still impregnated with the oil. I think it is and the chamber will be fine.

WD-40 is the oil I use for my guns (I find it here easily) and a great gunsmith told me it is good for steel and even wood.

Regards!

28 ga, hammerguns and all shotguns and rifles made by hands.
Waidmannsheil 🌿📯