Removing echo from double ender recording

I recorded an interview using iris.fm. I have two wave files for speaker 1 and speaker 2. Unfortunately speaker 2 was recording without headphones and forgot to turn on echo cancellation so their microphone recorded speaker 1’s voice coming out of their computer speakers with a slight delay. It’s about 30 minutes of audio so I can go delete speaker 1’s voice manually, but I was wondering if there’s any effects/processing tools in audacity that I could use to automate this. I was thinking I could inverse speaker’s 2 track and subtract it, but I’m not quite sure how to do it and whether it would have the desired effect. Thanks for the help!

The invert trick isn’t going to work: the echo is not exactly the same as the original, so they won’t cancel out.

Maybe AutoDucking could automate the deletion process.