Wow, I thought I knew all the Force powers - but I'd never heard of this one, or the one you plan on doing next. Its nice to be informed once in a while, thank you Aurbere!
Malacia requires a direct line of sight between the Jedi and the target, regardless of distance. However, if the target begins to retch, you may want to briefly avert your gaze, as this is almost always unpleasant to watch.
And we wouldn't want it to get in that lovely beard of yours, would we now Master Rancisis?