After months of hard use, water-repellent coatings can wear off. You can revive them with treatments like Nikwax Fabric & Leather, Polar, or Softshell Proof. [From $5; nikwax-usa.com]
It won’t replace a waterproof case, but send your phone to Liquipel and the California firm will nanocoat its internals, making it able to withstand dunks and soakings. [$60; liquipel.com]
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