It's used as a wood cleaning agent.
And correct spelling -
naphtha
Naphthas are also used in other applications such as:
* (as an unprocessed component - in contrast to reforming above) in the production of petrol/motor gasoline.
* industrial solvents and cleaning fluids
* an oil painting medium
* the sole ingredient in the home cleaning fluid Energine, which has been discontinued. You can purchase this type of naphtha at any hardware store.
* an ingredient in shoe polish
* an ingredient in some lighter fluids for wick type lighters such as Zippo lighters.
* an adulterant to petrol
* a fuel for portable stoves and lanterns, sold in North America as white gas or Coleman fuel.
* historically, as a probable ingredient in Greek fire (together with grease, oil, sulfur, and naturally occurring saltpeter from the desert)
* an additive to fuel (usually kerosene) for fire spinning, fire juggling, or other fire performance equipment which creates a brighter and cleaner yet shorter burn.
* to lightly wear the finish off guitars when preparing "relic" instruments.