Does Orb of Disruption prevent using abilities on self?
The Orb of disruption blocks the holder as well as anyone that visits them:
Disruption Orb :
Role-blocks anyone who visits the holder that isn't night immune. However, it will role-block you every night as well.
-From the How to Play
So unless they are immune to roleblocks, the holder can not perform any actions, including ones that self-visit.