I mentioned this to my mother today and she told me that if you fill the sink (or a pot or basin.. whatever you wish) with cold water and white vinegar, and put the greens in there for a while, they will get their fresh crisp-ness back.
Interesting. I did not know this. Thought I would share this with everyone.
x-posted to frugal_tips iguanarama iguanas naturalliving poor_skills