>>1713400>What is the correct practice here?Don't bother saying anything and stop being slow. That way by the time they realize what happened and get pissed you're already a hundred yards away and have no reason to care. The time gap between you coming into hearing range and you reaching them should not be long enough for you to warn them and them to react.
If the path is totally obstructed though, I might just coast (I have a loud freehub) or maybe drag the brakes - I don't live in an overcrowded shithole so it's usually quiet enough for that to cut through the almost-nonexistent ambient noise. If THAT doesn't work then it's sharp brake squeal followed by an annoyed "EXCUSE ME".