That would depend, George. If I wanted to preserve them for long-term storage then I would agree that salt might be the best way in some cases. It has its uses after all, and there are limits to how many ostrich skins I want to store in the freezer. (A limit of zero, in fact.) Is long term preservation of not-yet-mounted specimens a valid aspect of taxidermy? For the preservation of skin which is part of a mounted bird, I prefer borax or, for the big ones, one of the many accepted tanning processes. That should be no surprise to anybody, but I think that ALL knowledge is worth saving and if someone wants to learn how to preserve and mount birds using something like, say, tobacco juice, then why should I discourage them?