Okay but it’s not just for water
Here’s the weirder part. That same hole—so, yeah, the drainage one—you can actually use it to fix the lock when it starts jamming. I had no idea.
Apparently, if your padlock is getting hard to turn—not completely stuck, just stubborn—you can spray lubricant right into that hole. Not like cooking spray or something (don’t do that), but real lock lube. WD-40 works, or graphite spray. Whatever’s designed for tiny metal parts.
You stick the little straw into the hole and give it a quick shot. Doesn’t have to be a whole thing. And that lube, it’ll slide right into the mechanism where you can’t reach otherwise. I guess it gets between the pins and springs and whatever else is in there, and just… unsticks stuff.
I tried this once with an old combination lock I thought was toast. I was gonna toss it, but figured I’d give it one last squirt for science. Waited a few seconds. Tried turning it. It actually clicked. I stood there for a second like, “Did I just fix a lock with a straw?”
Honestly? Felt kind of powerful.

Why bother when locks are cheap?
Okay but let’s be real. Padlocks aren’t rare. You can walk into a gas station and buy one. They’re like, what, ten bucks? So why care? Why not just buy a new one when it stops working?