Yes, thanks for that tool Kent. It is a good find.

I do hear some abrupt decay patterns in the extracted audio on the Demos page of the link. (Aretha)
I assume this means the remainder of the signal was left in the mix.
That's always been my problem with vocal removal ..
It's not perfect .. yet, so often requires adjusting.

Here's another step to help the facade; replacing the vocals with something that helps camouflage the result.
This can be done using various tools, like match the reverb tail on the replacement track to the existing recording remnants (frequency-wise and time-wise), so they hide the artifacts .. stuff like that. The value of the extra effort depends on the need of course.

I do not work here, but the benefits are still awesome
Make your sound your own!