I think there are times when the smell of the skins may get you a bite when other lures or plastic won't. The question is how often and is it worth it if its only rare when a plastic tail won't do the trick. I think when the bass are really keyed into a vertain bait , like herring , you may get them to hit a skin jig if its set up right. Skins are a big pain. Some people use Condoms.
I think rigged eels are worth the effort. They catch well , they are tough to all things except blue fish , and again you get them free when your live one dies.