Intrigued by a post in the Collectors Corner I thought I give this Ballistol stuff a go, but which one do you use on blued action?

There seems to be loads of choice here:

https://www.ballistolstore.co.uk/weapon-care

Is it the Universal stuff or the Gunex?

Do you spray it onto a rag and then wipe the gun or directly onto the action and wipe it off with a cloth.

I have normally used an oily rag or a silicone cloth before...

Thanks!