Separating Audio & Video Podcasts in the Same Feed

Slightly complex question here ... with several possible solutions.

I have a few podcast feeds that combine both audio and video podcasts. I would like to synch only the audio episodes to my iPod.

If I try to synch manually, I have to choose every episode of every feed I want to synch in one go ... I haven't figured out how to add to an existing set of podcasts on my iPod. I don't seem to be able to synch everything then manually delete the videos.

If I synch automatically, I get all the video too, which eats too much disc space.

I've thought of the following possible solutions, though I don't know if they will work.

- subscribe to the a/v feed twice, and delete the video feeds from the feed I synch to the iPod;
- move the videos out of the podcast section to someplace else;
- ???

Any help? I'm an old Mac user, and have been using iTunes for a long time, but podcasts and iPods are new to me, so I may be missing something obvious.

Thanks!