I've had a hurricane lamp (like the one pictured below) for years but keep forgetting to buy lamp oil. Are all lamp oils the same? I guess I'm just going to try and find a bottle at K-Mart or Wal-Mart. My goal would be to use it for emergency lighting when the power goes out. Happens only a couple times a year so what kind of 'shelf life' does lamp oil have? Do these burn really clean? Anything I should I know to keep one burning properly if I have to run it for several hours (or days)? I guess having a replacement wick on hand is a good idea.