I own quite a bit of teak I bought back from Asia years ago. Not sure what they coated it with, but my furniture builder did backflips when I asked him what to protect it with. He emphasised that regular oiling is needed to keep the grain open and lustful. In short, teak needs to "breathe." Unless you had to coat it, I'd recommend just removing the coating and oiling regularly to keep it nice. BTW, my argument to him was, if you can't coat/seal teak, what do they use on many yachts to protect the trim?