Suggestions to recycle "Oui" yorgurt glass jars?

The light will not be very bright. Suggest glass paint or glitter glue.

I would use a paint that is not so opaque. Even several coats of any craft paint would let the light show through better than chalk paint, unless you are planning to use a light colored chalk paint. Even so chalk paint is thicker.

I covered them with polymer clay and use a battery votive.

This would work: http://www.hometalk.com/diy/decorate/rooms/tinted-mason-jars-29217874

I used the very same yogurt cups and used Sea Glass and Mirror effect spray paints and made votive cups. They are a great sized cup. I don't know that chalk paint would let light through in a pleasing way (I think it might show where the paint in uneven, I paint unevenly on glass)