DittoOK... My take here... Many many years ago primer manufacturers starting sealing primers to prevent moisture contamination. When the, later exposed as fake, armorer from Alaska reported misfires to contaminated primers it got a lot of press and people assumed it was real. It turned out to be a hardware failure he wanted to blame on primers.
At that time and once since I soaked 10 primers in WD-40 for several days and then put them in cases and fired them all and not only did they function properly but they also gave me the same accuracy as any other similar load from the same ammo... So... I have absolutely NO problem with worrying about using a penetrating oil in guns.
Nuff said.......