I have heard silicone will react with vinyl over time. I am not sure that is a good idea. I use e-6000 a small glob on a long stick. I stick it to the magnet and put it inside the mouth area quick. I also hold another magnet or paci to the outside. Once the e-6000 is temporarily holding the magnet in place, I pour in whichever glue is around, gem-tack, or modge podge to reinforce it. This is after I have put the modge podge in to do my hair and eyelashes twice. I use a neck pillow to keep the baby in position with the pacifier on the outside of the lips so that it will stay in position. Recheck it before letting it dry face down in your pillow to keep the glue on the magnet. (The e-6000 is like just a temporary holding dot for me. The real glue to keep the magnet in with is the gem-tac which needs to dry for 24 hours.
To get a magnet to stick to your pacifier, clip the nipple off down to the base of it with your scissors in a clean manner, then put the magnet to your dolls lips and let it connect with the magnet inside the head. Take a sharpie and carefully dot the magnet side facing up. Then remove the magnet, put it dot down into the hot glue (don’t burn yourself) in the center of the pacifier, add a bit more hot glue on and around the magnet, then gluing a small circular swatch of fabric over the magnet to the pacifier so that it protects the lips. In a few seconds when it cools you have a perfectly great pacifier for your reborns.