If it's a play jib I don't see anything wrong with it. If It's your only good jib I wouldn't do it. The snorkels I've seen that were in good shape will hold moisture ( if they help keep water out, they will help keep water in). The ones I've seen in poor shape will breath but they will let the light through, degrading the sail. A friend that just cruises his boat had a heavy sail cover type material added to the leech and foot of his jib so when he furls the only thing showing is that cover material. This is what monohullers have done for some time to protect the genny. This leads me to my question to you, big boats do it to make sail handling easier (big sail,few people) Whats the problem with taking that little jib down when your done?