If DIY colonoscopy is something you want to do more than once, doing some anal training with a longer toy is probably a good idea. Helps you learn to relax your muscles and get a feel for your insides, which would probably be pretty helpful for maneuvering a scope around. Oh and when you’re doing it, work the scope in a bit, then take it out, relube, rinse and repeat. It’s hard to work lube in that deep, doing it iteratively like that helps. Let me know if you have any butt questions, toying is like my main hobby nowadays.