I have used the "medium chill" strategy when I need to self-protect from my DD26. It is only a temporary measure while I get myself grounded again. Sometimes it makes things a bit worse, then things calm a bit. I am the one leaving the house to get the break as she refuses to take a time out in her room or away with a friend. Sometimes after I leave she leaves and may be gone for a day or two. And she may stay angry. When I feel stronger, and she shifts into a better place then the validation piece can work again.
A more constructive strategy, and one that I struggle to practice when i am anxious, depressed, exhausted is mindfulness. This allows me to step back and still be present. My tendency is to step back and back and back - maybe this is dissocation, maybe just intensely chilled. Here is a good link to the dbpselfhelp article:
www.dbtselfhelp.com/What_Skills.pdfqcr