Direct Share is a new feature in Android 6.0 that allows users to share content to targets, such as contacts, within other apps. It's surely a great convenience, but it also becomes annoying in some cases. So I wrote this Greenify prescription to completely turn off the Direct Share feature on Android. Click here to import the prescription and enjoy (ROOT NEEDED).
Also, you can add an IFW rule to do the same thing: Removing a contact from "Direct Share" panel.