I get the whole vinegar soak thing—I've done it a couple times myself—but honestly, I feel like it’s just a temporary fix. The gunk always comes back, sometimes worse than before. Maybe it’s just my hard water, but after a few rounds of soaking and scrubbing, I ended up swapping out the whole showerhead for one with metal nozzles. Rubber and silicone are fine for a while, but they eventually get brittle or start leaking at the seams in my experience.
About the WD-40...yeah, that stuff is way overrated for plumbing. It’s not really meant for anything with rubber or plastic anyway. I tried it on an old faucet once and it just made everything greasy without actually fixing the squeak. Silicone grease is better, but even then you’ve got to be careful not to overdo it or you’ll end up with residue everywhere.
Honestly, if your shower is spraying all over the place and you’ve already tried cleaning it out, sometimes it’s just time to bite the bullet and replace the head. They’re not that expensive these days and you can usually install one in about five minutes with a wrench and some Teflon tape. Plus, you get to pick a new spray pattern instead of fighting with clogged jets every few months.
Just my two cents—sometimes DIY means knowing when to stop fighting with old parts and just upgrade.