Wasn’t the German dub (based off the 4kids English dub) available on dvd with 5.1 audio mixes? You could use that to help remove the dub score from the English dub.
There’s also this. https://github.com/lazydevyo/SpleetGUI
I’m not sure. I don’t own those DVDs and I wouldn’t be too sure if the English track is in 5.1. The closest to the Japanese version is the French version, and I’m not sure if those have 5.1 audio mixes.