I have deleted my post above.
It's good to experiment firsthand. The first time, I dunked my BIC lighter into a full cup of water for one full minute -- without any tape. After a few quick wipes, it worked as if nothing had happened.
But after dunking for a full 30 minutes, the lighter no longer works. While I expect it will work again after the inside is all dried out -- that's not acceptable in the field.
The tape method is simple enough to use. Thanks, Timo.