Yes, there is. And even in the latest release - 2.94 RC3? - It's still in the same location in the Tools menu, and then under Songs. But -
When I use it, I click the description screen Next button and immediately my computer registers that OpenLP is not responding. (I might have some screens wrong. I'm currently leaving OpenLP running to see if it sorts itself out. and I'll update this comment if it ever does get itself sorted. Or maybe I'll have to force quit it once again and then I'll be able to update the names of the menus and screens.
This is the fourth attempt at using this 'wizard'. The OpenLP not responding message has occurred on each previous occasion, but I haven't been able to leave it running for more than about 15 minutes at a time. I don't know if this message would or should appear only whilst OpenLp is trawling through the list of songs to determine which songs are duplicates.
Rather than edit my post above, I'm going to add my comments here.
I was able to leave the 'wizard' running for close to 5 hours, albeit unintentionally. Unfortunately, there was no change in the behaviour of the 'Wizard'. It locked the application immediately and it remained in that state. It was still like that when I arrived at home over four and a half hours later. I'm fairly certain that it wasn't going to show any duplicate songs after that.
My conclusion is that this tool doesn't work as intended. Sad for me.