Okay, I understand [@Lyla]. How about making it more like touch telepathy? It won't work unless their in physical, skin to skin (or metal, idk) contact? But then the person will sense it working inside them - depending on how aware they are of themselves, surroundings, and magic itself - and can cut off the process of pulling their desires and fixations by ceasing contact. It give characters time to react, whether to avoid being forced to expose their wants or carelessly fall into giving them away.

[i]Edit: And I'll remove that pesky bit of surrendering through time.[/i]