L.C.
Put them right in the crock pot from the package -- add a little bit of hot water to the bottom of the crock pot and keep it on warm.
It works quite well.
The link below tells you that you don't need water, but I've found that a cup or two of hot water in the bottom makes for better dogs. They don't dry out.
http://crockpot365.blogspot.com/2012/04/hot-dogs-for-crow...
LBC