Give WatchPlayer a try!! You can add feeds directly on the watch and the developer implemented a direct download method on the watch that can download episodes as quickly as on the phone (when on Wi-Fi or LTE) (downloaded an episode of Accidental Tech Podcast, a fairly long podcast in 30 to 50 seconds!) - amazing app
https://itunes.apple.com/us/app/watch-player/id1170672458?mt=8
I am about to, just downloaded WatchCast and the podcast doesn't seem to be downloading at all on the watch, it is stuck at 0%. Hoping for a better experience with WatchPlayer.