Not so secret if you share!
And how do you use it?
I LOVE Paul's Extreme Sound Stretch. I used to run it in my Windows XP days, but when I switched to an Intel Mac, there wasn't a working binary. Until recently! This UB isn't quite as stable as the Windows version, but it still works.
Paul's Stretch is old school. You set the settings, and then hit render, and wait for it to chug out your sound. Not good for short stretches, such as you might warp in Ableton. This is for creating surreal, extreme stretches. Take a 10 second clip and make it 20 minutes, 20 hours, 20 days. Etc.
I love to use this as a starting point, and then hack up the stretch with tremolo or gating effects in a DAW.