Full disc rips perhaps. Unfortunately many remux don’t bother to pass through such tracks (though some do). Some groups like qxr often but not always may include them when available. Thing is they only really exist for movies released in the past perhaps 15 years from what I’ve seen.
Just be thoughtful. Accessibility is not seen as an excuse for breaking copyright. Take precautions.
Also if you’ve never done audio editing I’ll mention audacity the editor has a tool called “auto duck” that’s perfect for lowering the volume of other tracks in a mix when your select track with your voiceover makes noise To enhance clarity of it.