Overblowing is one harmonica technique that I've never been able to accomplish. I'm not sure if I've managed to do it even once in 30+ years of playing as a hobbyist. To rectify that, I just got a Suzuki Overdrive to see if it'll help me get over the hump.
If you're not familiar, the Suzuki Overdrive is a diatonic harmonica that has 20 holes in the cover. The holes allow you to place a finger to block off the air for either a blow or a draw hole so that all of your air goes to the opposite reed.
I did manage to finally produce a few overblows with it, but holy *#&$ was it difficult. I mean the process of forcing air through a blocked chamber reminded me of mouth inflating one of those long ballons you make ballon animals out of. If you've ever tried to do that, you'll know exactly what I mean. Like, you blow so hard that your cheeks hurt, you get light headed, and you're scared you might have a stroke from blowing so hard.
I know it should get easier as I develop just the right touch, but I have a hard time envisioning it getting easy enough that I'd ever want to incorporate it into playing. On a normal harp, would you really hit this much resistance when you choke off the blow reed and get the draw reed to sound instead? Or was what I experienced more a consequence of the Overdrive having an isolated air channel for each hole?
If you play overblows and you've tried the Overdrive, how realistic is the Overdrive experience for overblowing? I mean is this just a novelty or is it truly helpful as a learning tool?