Question about an episode

Can anybody tell me where I can find the episode "Duck Family Robinson & the Waltons"? I see it listed in the episode list but, I've never heard of it except for on this site. I'm pretty sure I have all Duck Dynasty-related dvds and it's not on any of them. I can't find anything on Youtube or anywhere else. The only info I can find is the little bit on the episode page. Any help would be appreciated.