DaVinci Resolve - replace "Um" in audio

Go to the Timeline menu and enable Layered Audio Editing. Then go to View menu and select “Show Audio Track Layers”.

Copy one bit of room tone you have and paste it to the first “umm” you want to cover, same track as your original audio, but on a new layer above the original. It will supersede whatever is underneath it when you play back. You can also quickly add crossfades at clip edges this way.

Easiest would probably be to copy a short average length clip and paste it across your take wherever there is something to hide, then go from piece to piece and adjust the length and placement to make it all seamless.

This way won’t (shouldn’t) take very long. Once you’re done you can turn off Show Audio Track Layers for a cleaner timeline look.