The mouse really only vibrates when you keep your hand on it passively for more than 12 seconds. So if it vibrates often, you must be doing this often, even if you don’t realise that. By taking your hand away frequently, you quickly learn to hold the mouse only when you really need it. Soon you will start releasing the mouse even before vibration occurs, reducing the frequency of the vibration.
The standard position should be hand OFF the mouse, not ON the mouse, that is what we are trying to achieve.