There's a series by an author named Steven Brust that I very much love (though he barely writes any more and kind of burnt his characters to the ground for... A lot of complicated real life reasons) but his main character is an ex-assassin named Vlad who actually began cycling through weapons every week or so for the express reason of not letting them become too psychically close to him so they couldn't be used for witchcraft against him.

To build on your idea, an assassin who has a mind name wipe all details of a job from his mind.

This could be an interesting group project, potentially. My character Urassaya, from "From Beyond the Edge of the World," has a natural magic for psychometry. Maybe she's enlisted to read the discarded weapons, but is having a difficult time doing so because of the weak, or lack of, connection to the killer.