I also agree with bot knife and fingernails - lol lol
However, I have learned that not all bot knives are created equal
The ones I have found to work the best come from Tractor Supply.
And just an FYI to folks new to bot knives --- they are one sided This is a good thread to remind folks about nose and throat bot flies.
Those evil little things migrate on their own into the horse's mouth.
I do keep that jowel hair shaved pretty close so I can see them but I can get away with that, living in TN close to the AL border. We have a lot of warmth much later into the year.
Sometimes I can't get them off so I smother them in whatever ointment I happen to have handy. It can be hemerhoid ointment, antiobiotic - just anything that will smother them and prevent them from moving, if you can't get them off.