Help. I have ordered a new leather cup washer from airgunspares, how should I treat it before fitting, I have looked in the archive and have seen dire warnings of silicone, and recommends for Neatsfoot oil which I have never heard of, is it possible to replace the leather with a PTFE ? which seems sensible even if it does mean wasting the £7.50 + postage. Any advice will be much appreciated.Thanks.