You could try lightly rubbing tea tree Cream in your hands, and run your fingers through the hair of the long-haired sow , it sometimes works! Though only putting up on your hands to transfer the smell
If I were you I would cut my long-haired pigs hair ! Hair is not digestible and if they eat enough of it it could cause gastrointestinal stasis, (tummy blockage ) and very few pigs recover from this