You can also configure Magic Lantern to not show anything when you're in Live View. The (outdated) manual states:

Global Draw

Choose when to enable Magic Lantern overlay graphics: (zebra, cropmarks, histograms, audio meters, ML shooting info…):

• in LiveView only
• in QuickReview (photo mode outside LiveView) only
• Both modes
• Disabled

Alternatively you can configure the "clear overlays" function:

Clear Overlays

Clear bitmap overlays from LiveView display.

• HalfShutter: Hold the shutter half-pressed, or the * button, or DOF preview for around 1 second to clear all the overlays from the Live View display (audio, zebra, crops, shutter speeds…).Tip: assign autofocus to * button (from Custom Functions, set Shutter/AE lock button = AE lock/AF).
• WhenIdle: In this mode, all the overlays are erased from the screen (100% clean display) when the camera is idle (i.e. you don't press any buttons).
• Always: In this mode, all the overlays are erased from the screen; you will have to change shooting settings blindly. You can still use the menus.Tip: this feature may be useful with External Recorders, since it removes the focus box and other graphics from the display.