Glass beads work great. And so does Salt .I use a mixture of the two to get the ballast I’m looking for. I will say this,if you use say soft plastic and add salt or glass beads. If you add softner to it . You will use a different amount of it depending on the ballast used . From my own experience I have found I can use less with the beads than I can with salt. From a use standpoint the beads will produce a far more durable bait than the salted one . Many folks here will agree with that.