I've had similar experiences with ceramic fixtures—great at first, but eventually the buildup returns. Magnetic descalers seemed gimmicky to me too, but I gave one a shot last year. Honestly, results were subtle at best. Silicone aerators are definitely easier for quick cleanups. Another thing that's helped me is occasionally soaking fixtures overnight in vinegar—cheap and effective, though admittedly a bit of a hassle to set up.
I've done the vinegar soak too, and yeah, it works pretty well. One thing I've found that helps even more is to remove the aerators entirely every couple of months and give them a thorough scrub. Here's how I usually do it: first, unscrew and soak them in vinegar for about an hour or two. Then, brush away the loosened deposits with an old toothbrush. Rinse thoroughly before reinstalling. Takes a bit of effort, but it's worth it in the long run.
Also, if you're open to slight upgrades, look into fixtures with removable silicone nozzles. They're designed specifically for quick cleaning—just rub your finger over the nozzle tips to clear mineral buildup. They won't completely eliminate the issue, especially if your water's really hard, but they significantly cut down on maintenance time.
