This is something you might get a lot of different opinions on.
If you are using a tightly patched ball and pyrodex or black powder I dought it is necessary I have hunted for many years with a renagade 54 cal. and have killed deer two weeks after I first loaded it with out a problem; the only thing I do is I find some neoprine or plastic ear plugs and pull them off the plastic band that goes over your head I put one of them on the nipple to keep moisture out right away when I take the cap off and let the hammer down to rest on it. Lee