The wire device I came up with to hold plastics from slipping down jigs,is easy to make:
Get some 24g coated wire used for flower arrangements, cut a piece and wrap under the eye once around as shown. Cut one leg as short as possible to the eye shaft and use pliars to tighten further.
Form the other leg into an L shape that will swing into the front of the bait. I use the same wire L for skirted jig to hold plastic trailers on, except it is held in place by the skirt tie.
I prefer ordering ballhead jigs that have no grub holder seeing as how they aren't needed and do less damage to grubs. The wire is easy to attach and all jigs I carry have them.