I find cast iron very easy to take care of -- much easier than non-stick (but perhaps we use our non-stick for only messy things). Dump out the food, wipe it out, put back on the still-warm burner, put in some oil.

If something particularly hard to clean was in there, I do what scouts do on a campout: put an inch of water (with a little oil) in and set it to boil, then go back to the "wipe it out" step above.