I will say that I have only really strongly noticed ghosting one time.

I smoked some Peterson Irish Flake in a pipe (I believe it was a cob actually) and the next day pulled it out and packed it with Elizabethan Mixture. I could taste the Irish Flake very clearly.

I've heard cobs don't ghost nearly as bad so it kind of surprised me. Of course Irish Flake is a strong tasting tobacco.
I don't know if I just didn't clean it good enough or what. That may well be the case.