There are a lot of homemade cleaning solutions. The one Chap mentioned works great. Then there is MAP which is Murphy's Oil soap 20%, Isopropyl alcohol 40% and Hydrogen Peroxide 40%. This can cause flash rust so be careful.

As of late I have been using Simple Green. It is a cleaner like 409. You can buy the stuff by the gallon and mix your own strength. I like a strong mix and it really cleans out the fowling.