I have a level 100 Sceptile in Omega Ruby, traded over from my Alpha Sapphire game file, can using an X. Accuracy allow me to land attacks more often?
No. They are two different functions that don't interact with one another
The X Accuracy (Japanese: ヨクアタール Hits Well) is a type of battle item introduced in Generation I. It temporarily boosts a Pokémon's accuracy.
Source for X Accuracy
Obedience is a Pokémon's willingness to listen to its Trainer's commands. While Pokémon usually obey their Trainers, a Pokémon may disobey if it does not respect its Trainer
Source For Obedience
Neither page mention them interacting in any section. I've also played thousands of hours of Pokemon, and never seen or heard them interacting this way before.