No Collars in the House
I first started taking the collars off my Danes in the house because I just liked the way they looked without them and they seemed to be a lot more comfortable without them on. Also because we all consider our dogs to be our kids so it seemed wrong to have a collar on them all the time.
After a while it became a habit that once they came in the house after a walk I would just take their collars off.
And then something interesting happened.
When all know the routine, when they know it's time to go out they get all excited and jumping up and down, let's go, let's go, and inevitably one or both will run out the door because they want to be the first on that walk.
But without fail each time either one would run out the door they would turn around and come back and sit and wait for me to put their collars on.
I had inadvertently trained them to not go out of the house without their collar on. No collar was an instant recall every time.
Give it a try I think your dog will like it.