Yes it's true.Lye was used and circulated through the pump and locomotive air system.We did it at Golden Spike about every eight years.Your right it CAN BE dangerious if done improperly.Lye is nasty stuff.When mixed it generates a tremendious amount of heat.So eye and face protection is important as well as clothing.It can boil up and spatter.We circulated our lye from a ten gallon
resepticle.And of course it has to be flushed with water after the process.As an added note because of esroline the use of lye cleaning has been drasticly reduced.