How can I remove deleted podcast episodes from iTunes?

I have a MacBook Pro, mid-2009, running the latest Beta version of Yosemite. iTunes version is 12.1.2.27.

I'll explain the problem, then give you a small amount of background to explain how things got the way they are.

I have a number of podcast episodes that have been deleted from my hard drive. They are very, very gone. Yet, iTunes still remembers them, and they show up as being on my hard drive, until I try to "Get Info," at which point, iTunes helpfully informs me that the file is not where it thought it was, and asks if I'd like to locate it. I say no (Cancel), and then try to DELETE the non-existent 'file' out of iTunes...it it does absolutely nothing. Because the file isn't there, and I have unsubscribed from the podcast and deleted it from My Podcasts. There are ~150 of these, which I'm calling "Orphan Podcasts." (I found them by creating a smart playlist with all podcasts with a play count > 0 that are located on my disk.)

What I want to know is if there is a way that doesn't involve completely starting over from scratch to get rid of iTunes' knowledge of these deleted episodes.

Now, how it got this way: iTunes has an upper limit of how many episodes of a podcast it allows you to download. After that, you have to go to the website and get the archive. I do that, and then import the MP3s into iTunes, mark them as podcasts, fix the release dates, and then I can listen to older episodes as well. I didn't understand what "Save Episode" did when that first became an option in iTunes. I thought it was a way of keeping iTunes from deleting episodes I hadn't listened to, yet. It wasn't. It was a way of getting it to keep episodes you HAVE listened to. ANYway, I subsequently deleted the files off the disk after I'd listened to them, not realizing that iTunes would be unable to handle that. iTunes dutifully thinks it needs to hang onto them because I marked them saved. I can't UNsave them because that's only accessible from My Podcasts, and I've long since deleted the files and (usually) the directories.

I understand that there may not be a way to do it without completely wiping iTunes' data files and starting over, which is just simply not an option (I'm not going through all my organizing again). But if there IS a way to do it, I'd like to know. Thanks in advance.