My wife has a butane hair curler, specifically for use in the car. The marriage-saving value of an appliance that allows departure from the house, while final preparation for an outing continues, should not be underestimated.
The "woof" sound from this thing when it finally ignites the accumulated cloud
of (enclosed) butane concerns me more than any propane
appliance in an RV.
The ideas of heat output rate and energy source choices lead logically to an obvious device: the propane-powered hair dryer, based on a common shop torch and with a fan run by a cordless power tool battery
pack. It would be standard gear at Tim Taylor's "More Power" Mobile Hair Salon