I understand the mess of threads when washing a bunch of fabric. We had a flood in the basement, and everything was wet and some was moldy. So, any sewing of edges was not an option.
I've purchased some hand-made batiks with zigzagged and others serged, so I was going to suggest that. But the baste the ends together sounds like that may work, too, and it would be faster than zigzagging. I'd wear gloves to do it. It doesn't have to be a perfect seam, so any loss of sensitivity from the gloves wouldn't matter. You can buy the gloves that look like plastic bags in the food service section at Sams/Costco. Then there are the surgical gloves, and if you're sensitive to latex, there are latex free surgical gloves.