Crating for a cool down period is fine. Time-outs are not the same as a cooling down period though. A time-out is a behavioral modification method to change a dogs behavior...to create a whole set of new behaviors. The usual time-out period (total social isolation with no human interaction) is 3 days. Severe cases may go as long as 7 days. There are a couple of shorter time-outs for specific issues. These should not be attempted without the guidance of a qualified behaviorist.