I think a time out is a far better way to handle a child who is hitting or misbehaving than yelling at them or snapping and spanking. A timeout will let everyone get back under control. I'm always surprised at people who are adamantly opposed to any kind of punishment, yet whose children are so miserable to be around, even the parents don't like them. What a sad life for that child. (Not saying that is the case with the original poster.)
We don't actually time our time-outs here. The kids just know they can leave time out when they're ready to talk. My kids are 5, 9 & 9 and I can't even think of the last time we've done a time out. I'm sure my 5-year-old will get one again sometime, but she's a pleaser, so has not interest in being sassy or misbehaving. Sometimes she'll talk in a rude way and we just ask her to stop and she'll apologize. If there is a time out, once everyone's calm, I let my kids come up with the "better" way to handle whatever it was that got them in trouble. As for kids not staying in timeout, that never happened with us, but I think if you just kept putting the child back in time out he or she would eventually stay and it would be less of a battle each time (the goal, of course, being no timeouts).
I do want to point out that not all parents who are against time-out are against any discipline. I agree that permissive parenting can be detrimental to children. Children need boundaries, and in fact, beg for them if not clearly defined.
Calmly holding a young child who is learning to control their body while giving them tools such as angry words, a pillow to hit, and loving arms is a way of setting firm boundaries with a child who is learning that people are not for hitting.
A screaming child who doesn't listen to my boundaries or direction is a clear indication that we are becoming disconnected. What can I do as the adult, the parent, to reinstate that connection? A child who is well connected usually wants to cooperate. Of course, a toddler or preschooler does not always want to cooperate no matter how strong the connection is, but this is a developmentally appropriate stage, and one that can be handled wi firm boundaries, loving arms, and lots of tools that do not equal punishment.
Letting a child know that they are welcome to take a break and hang in their room if they are feeling upset, frustrated, or angry seems like a great tool, not a time out. Time outs, when used as a forced punishment for misbehaving can threaten the connection I have with my child, so I try very hard to not resort to using them.
But, I am not a permissive parent. That would also threaten the bond I have with my child, as well as create an unsafe environment, as I have a 4 yr old who is learning to control his body and at times needs the boundaries dh and I have established.