So, how long should you wait? Longer than you want to. That’s the rule.
Set a calendar reminder for three months from now. Then forget about it. Go plant some flowers. Watch the grass grow. Watch the wood dry.
And when that water finally, finally soaks into the grain? Grab your paint, your drop cloth, and your victory dance. You waited. You won. And your deck will look amazing for years to come. You’re welcome.