You are truly asking for trouble tying a rope around yourself.
For example if you were towing a friend and the tide pulled your friend onto the other side of say a channel marker you would have no way to release yourself from the rope. This could become a nightmare situation.
Always have some sort of quick release incorporated into whatever towing system you use. I have used a variety of quick releases, but the best methods I have found are a quick release belt if using a waist mounted tow, a snap shackle or a kite surfing quick releasing shock cord if using a kayak mounted system.
The New South Wales Sea Kayak Club website has a basic skills section that may be worth checking out. There is a small section with a short video on towing.