ESP Super Floss
Pop-ups which have been pierced and threaded onto a hair rig are more likely to absorb water and lose buoyancy.
E-S-P Super Floss has a wide, flat profile which grips the pop-up securely without cutting in, even when the bait has swollen slightly.
The pop-up can then be tied to a rig ring with 3 or 4 overhand knots.
Rather than using super glue leave about 1cm tails at the end of the floss, then using a lighter burn back the ends to form small hard blobs, giving total security.