where did you find an inside rocker?! I have looked everywhere for one!

1 is old. 1 from garage sale. One from Nebraska furniture mart..

A good exterior paint will hold up fairly well. Depending upon the wood your chairs are made of will also determine how they weather. Marine paint and poly would work even better. Make sure your connections are glued well, or let the poly fill in when painting, if not loose. Outdoor furniture always needs maintenance, even sold as patio furniture. I can't keep up with it, especially without a porch or patio cover.

try an enamel paint.

Do you have a Cracker Barrel Restaurant in your area?....they sell both varnished and painted wooden rockers which are outside on their covered porch. I would imagine you could go to the paint store such as Ace Hardware or Lowe's and ask the paint department what you should use to paint your chairs for outdoor use. Would have to be something that would seal or waterproof the wood, I would think.