If the clicking works for you & your grey recognises it then yes by all means stick with it.You can actually use the clicker method to train your grey.The clicker is just the one you would buy to train a dog.If you do a search in the search box directly at the top of the page it will bring up previous threads for you to have a read through.
Here's a piece i wrote previously on kissing
As affectionate as it may seem, it is inadvisable to kiss your Grey.
It is highly unlikely that our bird will pass anything onto us but there is always the possibility that we may pass something on to them through saliva, germs on the lips, sneezing etc..
Something small to us such as a cold virus can be potentially dangerous to our birds, so why take the risk ?
There is always the danger no matter how well you know / trust your parrot it may & can bite your face.
Anyone who says that it can't happen with their bird just doesn't know the full scope of what a parrot can do when it wants to.If a parrot were to bite, the owner would mistake it for aggression which it isn't.
There's plenty of other ways to show affection to a parrot,A head tickle/scratch, a gentle caress of the beak with your forefinger & thumb,what ever your grey is comfortable with