OK, I've pickled some purslane, and here's the review. I put some well-washed raw leaves that I picked off the stems, and stuck them in a pint jar with some cider vinegar, 3 peppercorns, and a couple allspice seeds. It wasn't much, just about half a jar. Then 2 days later I fished some of it out and put it in my salad. It was okay, but tasted mostly like vinegar. I added more leaves to the jar, and put it back in the fridge. Maybe tomorrow I'll add a little sugar to see how that works out, and perhaps some mustard seeds or more allspice.
So far, edible but not a knockout yet. But I'm working on it. If I get it good enough, I'll know when Peter Piper purloins my pickled purslane.
Sorry, couldn't resist.