Though it can be good training, leaving a slave bound alone can not only do them harm physically but mentally. I was once left alone for a period of 6 hours and had a memory relapse from being alone, bound in the dark. It is importaint to have an emergency setup or someone there to check up on your slave periodically.
Ita always importaint to find where your lines lie to real life. Its a life style, and just as normal and natural as anything else. Master and I have some routines that may be strange to others, but for us it is simply how we live.