I appreciate the suggestions...
Some of these we have tried, such as negotiating what chores should belong to difficult child. difficult child, naturally, feels that NO chores should be her responsibility and that somehow, being asked to do anything at all is unfair and an example of how cruel and abusive Mom and Dad can be.
At one point, we had a problem with all the bathroom towels disappearing into difficult child's bedroom. She would use a towel, throw it on the floor and then get a fresh towel next time she needed one. The wet, dirty towels never made it to the laundry...and would sit under difficult child's bed and get mildewed. After I found one of my best towels mildewed under her bed - I had enough! I went out and purchased all new towels for everyone...I got nice, plush towels for the master bath and inexpensive Wally-World towels for the kids - a different color for each child. difficult child still does not take care of her towels...but that's become her problem.
The theory behind "each person doing their own dishes", I suppose, is that each person is responsible for their own mess - and because no one wants to eat off a dirty dish, that is motivation for cleaning up.
I have learned these many years that difficult child does not care about being dirty. She does not care if she goes weeks without showering or washing her hair. She goes days and days without changing her socks or underwear. And once, when she had a nosebleed in the middle of the night, she did not bother changing the pillowcase. She didn't even flip the pillow over! - but went for an entire week sleeping on a blood-encrusted sheet. It was absolutely disgusting!!!
My decision regarding the dishes is a choice for my own sanity. I do not want to wait for difficult child to finally "get" that something is dirty. I choose not to be subject to her passive-aggressive game playing (ya know, where she pours an entire bottle of dish soap down the drain, runs the hot water full blast for an hour and then claims we 'ran out' of hot water, 'accidentally' dropping and breaking the dishes, 'accidentally' flooding the kitchen floor) and then being stuck cleaning up the kitchen later anyway.
My rationale is that if difficult child chooses to behave like a toddler - she can have the priviledges of a toddler. She has no cell phone, no computer priviledges, no after school activities, no allowance - nothing.
If she would like to be treated better - she can "do to get".