I’ve used a combination of glues. Hot glue is a pain to get a thin enough line of but seems to stick to every brand of paci. For some reason, I couldn’t get e6000 or super glue to stick to the duck one (Dr Brown). I ended up using hot glue and taking off what extra I could with my miniature pocket knife. For most of them, though, I’m now leaning towards hot glue. It sets a little faster and seems stronger. They might not hold up to rough, rough handling depending on the details but seem pretty secure. The cat tails took the longest because the glue simply wouldn’t stick at first. I threaded most of the beads on them also to make them less likely to lose beads.
If anyone finds more ideas, let me know. I tried to search some online but couldn’t find what I wanted so I’ve been just playing around with them. I wanted a smaller paci for Kissable (17") so that is next on the list. I tried clear suction cups for tiny ones last year so I may try that or just sculpey some backs.
PS Baby consignment shops sometimes have containers of used pacis for sale. I don’t like Avent pacis I found out since they are flat on the mouth instead of curving. It might be okay in a real baby’s mouth but reborn lips don’t give!