In order not to leave any traces, when you do something, you should do it with your whole body and mind; you should be concentrated on what you do. You should do it completely, like a good bonfire. You should not be a smoky fire. You should burn yourself completely. If you do not burn yourself completely, a trace of yourself will be left in what you do. You should not have any remains after you do something. But this does not mean to forget all about it.