Reconditioning outdoor furniture

Could use some words of wisdom from you fellow LJ on the best way to recondition outdoor furniture before painting them.
Friend found a couple of patio deck boxes that have been outside almost forever. The wood may be teak, but hard to tell since the coloring of the wood is sun-bleached out. The wood itself is still good and strong, so that is no problem. But they need some sort of treatment before they get painted because they are so dry. Did a spot test on them with stain, paint, sealer and primer. The paint and stain just soaked straight in and would need repainting more often, while the sealer and primer gave the best results of them all.
Was wondering if a light coat of BLO and long drying before painting them would get them back to a reasonable condition before painting? Or just stay with the sealer / primer? Thanks for your help.

-- Deeds not Words.