thats not really helpful though against mmm if mmm comes very early. A better suggestion would be to either try and bumrush his force from the side with an angry pack of banelings (with speed upgrade is NECESSARY) or just burrow even as low as 10 or less banelings at your choke, wait for him to come up with his mass of shit and explode while burrowed. also note they should be in a line to hit the entire force all at once. Instant mob death, mop up with a paltry counter force maybe also of banelings and then immediately attack his base.
Don't forget the only thing that would help him at that point is a raven, he likely wont be using a scan sweep on your choke. Note that even if I'm wrong about the previous sentence, then just burrow the lings somewhere else that he'll likely be walking past. Like a few feet in FRONT of the farther ramp that he'll definitely not scan. plus, the raven will usually hang back and wait for you to burrow roaches right in front of him anyway so you should absolutely still be able to pull of the explosion. You don't even have to explode them underground, just burrow them hiding outside of your nat and have a few force up top that they'll be busy with, come from behind with banelings as soon as the fight starts.
If you pull off the baneling explosion, which isnt hard at all, you're almost guaranteed to win if you have a medium sized force of anything. especially if you can even pull off a burrowed roach attack to get past his wall. extra points if you burrow two sets of banelings at both ramps to your base, detonate the one closest to your main first and as he retreats do the farther one.
edit: I should mention that I find it downright hilarious that I always have these involved and complicated strategies that I can name off the top of my head, then I go to play the game and somehow I always go for something stupid simple like straight teching to mutas while defending with a paltry amount of zerglings and I forgot to make a queen or something. Damn I suck.