i find dish detergent very messy. Like some others here I use mineral spirits, but only on cogs and severe messes. It's very good for cleaning a tooth brush or whatever else you may be using. For most applications, I've found the tri-flow citrus degreaser very useful and not too abrasive (apply to rag first).

http://www.triflowlubricants.com/Cit...er/citrus.html