For the last 2 years I've varying for using golden letter opener a 1 sideded dager which has been melted to double sided. And the 3rd is natzi dagger which I've been using for serious craft work. The letter opener is my travel athame. My question is can something like a natzi dagger affect the person? For this I'm refering to athames
It is very unlikely that using such a weapon could corupt you. A possible exception to this would be if you do something improper, like torturing or killing something or someone. Doing this could bring out any latent spirits in the knife. (though I should think that you would not do such a thing anyway)
It depends. If it is one of the modern replicas of a SchutzenStaffel dress dagger, the only risk is what might come from closely associating one's self with something that has symbolized evil and brutality for more than half of a century. It's not a set of symbols and associations which I would ever care to make part of MY life. And, of course, the mere possession of a such replica in Germany would result in ten years imprisonment.
If it is an ACTUAL SS dagger, left over from the war, about the only way I could think of to cleanse it effectively would be to toss it into a blast furnace and reduce it to molten metal...