I have not tried every kind of cold blue, but I have used an awful lot of them. None, repeat none, will last. Even when used like rust blue, with boiling, carding, etc., they will wear off in short order and even faster when oiled (the main purpose of bluing is to retain oil and prevent rust - appearance is secondary).
So folks spend a lot of time and effort on magic ways to get good looking results from cold blue. Then they post on sites like this, telling us how they had great success and Jim and the other naysayers are full of it. Then the blue wears off at the first shooting session, and we never hear from them again.