How to Transfer Podcasts From Your iPhone to the Computer

I've accumulated a lot of limited time podcasts downloaded straight to the iPhone, which have now all vanished from the iTunes store. Trying to save space on my iPhone by taking them off, but I can't find a way to save them to the PC.

Tried Googling it, and typically all the results seem to be shifty looking ads for shifty looking software. Anyone know how it can be done ?