Just had a thought... I used to get stud-style earrings at Claire's that were magnetic- they had really strong magnets on the stud and the "back" that held them together. They stayed on well although they moved a little if you weren't careful, and I could wear them for several hours although not all day, but they were a decent solution to the problem that clip-ons can't be delicate studs like diamond or pearl. Well since these were from Claire's they were CZ but you get the idea. Maybe see if they still sell those?