Okay, so. It was rather impossible to keep track of what exactly you found before, but like one month ago they changed how Accessory enhancing works, so you no longer need to fodder SSRs that you find. So let us have a look at some statistics, since I haven't foddered a single SSR Accessory (except the ones that came from Union events, to not mix things up) since then! Due to AQ events, this is roughly 53 days worth of drops.

Total SSR Accessory drops in this sample: 316
Total number of Devil Accessories: 60 (~19%, notice that 50% is theoretical maximum since you can only find one per run)
Total number of jackpots: 10 (~3%, ~17% of Devil Accessories, ~29% of Devil Accessories which could have them since Rings and Earrings can't)
Amount of useful jackpots: 0

Distribution of different types:
Ring: 13 (~22%)
Earring: 13 (~22%)
Tiara: 7 (~11%)
Bracelet: 7 (~11%)
Brooch: 5 (~8%)
Necklace: 15 (25%)

Since I did this in a rush, here is a way to verify if anyone cares. My notes:



Each line is one page.

Video to check the notes:

Other interesting tidbits:
Number of two Double+/Triple+ Accessories: 6 (~2%) (1 Tiara, ~0.3%)
Number of three Double+/Triple+ Accessories: 0 (0%)
Number of Drop+ Tiaras: 4 (~1%)

Now, this is faaaar too small of a sample to be "the true droprates" or something, but it gives you some idea of just how depressingly low chance it is to get jackpot Accessories. But it should be enough so that if anyone tells you "lol u should have 15% dbl and 10% trpl on every hime" or "lol my regular team runs 30% drop+ bcuz they have drop tiaras" you can tell them to shove that horsecock up somebody else's arse.