Alcohol doesn’t do a very good job of removing grime from hairsprings. Also if cleaning the hairspring while still attached to the balance assembly the alcohol will soften the shellac used to hold the roller jewel in place. For this reason alcohol, when used as a watch rinse should be used as a quick rinse only and pallets and balance should be dried immediately. Some people soak hairsprings in Naptha (Ronson lighter fluid) to clean them. Naptha won’t soften shellac at all. Also soaking dirty hairsprings in regular watch cleaning solution and then rinsing thoroughly works well.
Remember though that Naptha must always be used with caution as it’s extremely flammable.
Hope this is helpful Chaplin37,