anyone with teak spray rails...

[Garrison]

Guys,

I am wondering the most functional way to seal and finish teak spray rails for a good look and sustainability? I have been oiling them but am curious if anyone has varnished or sealed with anything other than wood oil. They get alot of abuse and weather so not sure if its worth the time and effort of varnishing every 4-6mos. Any input or first hand knowledge would be greatly appreciated.