If you're serious about it, the way that I (accidentally) found that works is to keep some spiders and roaches as pets. I used to be the same way, involuntarily flinching whenever a large enough insect would crawl on me until I adjusted to being around them all the time. The roaches and smaller spiders don't trigger any kind of involuntary reflex anymore. I do still flinch when the largest spiders (> 5 inch leg span) move very quickly while I'm doing maintenance but I'm pretty okay with that, especially because one of them could put me in the hospital.