Fresh identity with coins

Recently I've bought a character and I've even renamed it, but friends of the previous owner still have me on their friendlist.
Is there a way to "remove" my character from other players' friendlist? Does double change of faction do the trick? What about the "recustomization" option?

Swapping factions will make people who have that toon on flist say "unavailable" or "unknown" and fix the issue you are describing. Other than that, you can't force remove toon from other peoples flist.