They already are hard, and stick out and are about 8mm^3 in size and towards the front of the crinkly bits. Surgical spirits eh? Ouch, i hope it doesn't hurt too much - I had to use it when my piercing got infected, stung like a bitch!
Most importantly, what can be done to prevent this?
They usually occur in horses who are not in alot of work such as youngsters or horses who have had a break from work.You need to ensure that you don't overgirth your horse and that you pull out each foreleg in turn to ensure there is not skin being pinched up in the girth which will cause more sores.You could also invest in a sheepskin girth sleeve to help prevent the girth rubbing.