RE: cleaning engine
Couple of things to add to what kdheath said:
1. Do this OUTSIDE. The fumes WILL get to you.
2. DO NOT USE THE CROCKPOT FOR FOOD. The antifreeze gets into the pores of the liner and will contaminate (read this as poison you) anything cooked in it afterwards.
3. Dispose of the antifreeze in a safe manor. Animals (and kids) like the sweet taste - it will kill them.