I wouldnt do that. Crock pots are pretty cheap. You can get them for $20 or less. And cook it in the garage or outside. The fumes would be hard to tolerate. I use a deep fry basket to hold the bigger parts and a metal tea thing-a-ma-gig for little bitty parts. I check them at 3 or 4 hour intervals. On stuff that is really stubborn, a little tooth brush scrubbing might be needed. No need to cook it over night. If you get it too hot, or cook it too long, the aluminum will turn a dark grey. Doesnt hurt anything, just discolored. The dirtiest muffler I had took about 10 hours total. I just checked it at about 4 hour intervals and rinsed it off every now and then and scrubbed a little. As far as I can tell, the NON-environmental anti-freeze works best. Others have tried the freindly stuff and said it didnt work. I dont know. The best use I get out of this process is cleaning 4-stroke heads. Once it loosens up all that carbon its easy to clean off and do a quickie valve job. Fixed a bunch of cantankerous old 4-strokes that way.
Edwin