You could use exterior house paint in a paint sprayer. My DH used white exterior latex on an antique wicker( parts look like twisted paper so pretty fragile) It sits on a very very small front porch and is not protected from a hard rain. That was 3 or 4 years ago and it is fine. I have a wicker settee on the other side that I spray painted with regular spray paint 2 years ago and its fine too. both get a bit of protection from rain and snow but not much.
Heck if he threatens to throw it out, paint it and use it until it wears out!

I have wicker furniture at our lake cabin that my grandparents built. My grandma put so many layers of paint on the wicker chairs that were on the screen porch and weather was never an issue. She did have the screen porch enclosed with windows before she died (20 years ago) but let me tell you, those chairs are still going strong. They were on the porch (unprotected) for almost 30 years although they did get moved inside for the winter months.

It should do OK with a protective paint on it, but direct sun and rain will take its toll.

The most important part to protect is the bottom of the feet. If they sit in standing water or on moist ground, they will absorb moisture and be the first area to rot.

Thanks for the help...
I'm going to give it a try ~ will post pix when done. :)