A “jackpot” treat is a food, toy or any other reward your Griffy will find irresistible. Something they will drop anything to get. It should not be available to them at all times but saved for special circumstances. It can be a perfect distraction!
In the case of mild separation anxiety (or the classic escape artist when you try to leave your house) you can give them a stuffed Kong or other jackpot toy. When they take it from you and head for a spot to enjoy it, quietly leave. Remember to pick up toy when you return so they associate you leaving with something good.