You either shoot snot rockets, or you don’t.
I do.
The technique is to hold one nostril shut and forcefully exhale air out the nose, clearing the open nostril of all debris. It’s healthy and good for you to expel all that bad gunk, although don’t be so forceful that your ears pop.
The best way to learn the technique is by running in the rain. That tends to get the fluids flowing, and if you are sloppy, cleanup is much easier. Probably alone is best.
You should learn this. It’s good for you. Sometimes you just need to trust me.