On my computer, CTRL+M shortcuts are not clearing formatting.
On Chromium 49, that shortcut opens the IME selector on Flow and does nothing on an page edited with VE.
On Firefox 45, it mutes my tab on Flow, and randomly mute the tab or clears formatting on an page edited with VE.
Config: intl configuration for an Azerty 105 keys keyboard for PCs (by default when I've installed my machine), on Xubuntu 14.04.
With that disposal, it is not possible to use CTRL+\ to clear formatting