It should not be done by Christians, because the name of God is holy. Even when there is no bad intention, it should not be done, it is a bad custom.
Of course, when a person does it without deeper reflection or intention, it is not a grave sin. It becomes a grave sin when it is done with full awareness and deliberate intent. But if it is done out of forgetfulness or without being fully conscious, it is not a grave sin.
Nevertheless, it is a bad custom and should not be continued by Christians.
Dear visitors of Gloria Dei and all who have already written or who will write a personal message to me. I am grateful for your attention, your kindness, for your spiritual support and especially for your sacrifices and prayers for me. God may reward you!