I used to do it to people when I was younger... it takes a willing subject. I'd ask the person to look at my eyes and blink everytime I said a number. When I got to fifteen or so I'd start to include suggestions with the number... "relax, listen to my voice, relax, your eyes are getting heavy, relax", etc. When their eyes were closed I'd take them on an 'elevator ride', saying that every floor we went down would put them deeper into this relaxed feeling. It was always a pleasant thing, never frightening to them. When we got to the basement... "you're as deep as you can go...", I'd ask them to remember a birthday party when they were five or some such thing, then give them a post-hypnotic suggestion, that they'd want to try to write backwards or tear up a piece of paper when they heard a certain word, something harmless. I'd tell them that when they heard me snap my fingers they'd awake feeling better than they had all day, and they would- I never had a person not enjoy the experience.