First, here's a couple links. Please note the third link talks about throat & nose bot flies. The difference between them and the common bot fly is their egg SELF-MIGRATE into the horse's mouth How to Get Rid of Fly Eggs on Horses | eHow.com Lambriar Animal Health Care - Equine Bot Fly Chart
Throat & nose bot flies http://www.ctahr.hawaii.edu/oc/freepubs/pdf/LM-10-3.pdf
Once you read these articles, you will understand why the eggs should be removed from the horse.
Soaking the hair in warm water
and quickly scraping the eggs off is the easiest way. Using warm water tricks the eggs into thinking the horse is licking them, so they release. Soon as the water cools down, the eggs stick back onto the hair; that's why they don't come off in the rain,
I have seen Throat Bot eggs this year; didn't see them last year. You have to pull the jowel hair backward pretty hard and look close. Looking in the daylight is the best. Unless there's a ton of them, it's really hard to see these particular eggs under the barn or arena lights.
If I can, I cut the hair with scissors. If the eggs are laid in such a way that I can't get the scissors in there (you can only do so much clipper clipping before the horse is bald - lol), I will smother them with some kind of ointment. Anything -- Vaseline, A&D, antibiotic, just any kind of ointment you can get your hands on. Vicks would work too.
I use bot knives, others prefer the blocks. Bot knives are one sided and they aren't all created equal either. The ones that work the best for me come from Tractor Supply but that could change by the time I need to buy more. They get dull pretty quick when four horses need scraped - lol
Bot eggs and tapeworms are the foundation reasons why the equine world worms "after the first hard frost", not before.
There are folks that take the Ho-Hum attitude of not removing the bot eggs "because they'll be there again tomorrow". True enough but the more diligent we are in removing the eggs, the better the chances they won't end up in the horse's mouth to migrate into the stomach and hatch
I hope this helps and while I did chuckle reading your post, I only chuckled because that was how I felt about ticks when I first moved south and found those miserable things covering my horses, one spring
You'll get used to picking them off. Some years are worse than others. This year I hardly found any common bot eggs, but did find a few throat bots. Other years the horses can come in at night and look like I hadn't cleaned the eggs off them for several weeks.