As one anecdotal point: I waited months for mine to go away, and eventually got really frustrated with it and brought it to the store. They took it to the back

As one anecdotal point: I waited months for mine to go away, and eventually got really frustrated with it and brought it to the store. They took it to the back and somehow their air can removed what my air can at home could not. About a year since I did that and the key funkiness is slowly coming back for the last two weeks. Hopefully I only need another Apple Store trip and their compressed air to fix it.