I've heard various things about the beads.
What about sewing the beads in their on separate bag that you can insert into the bib & seal it with velcro? That way the "bead bag" could be easily removed when you washed & dried the bid & then just inserted again when it was ready for use. You might even double bag the beads if you are afraid of them somehow falling out.
Here's the link to Rob Appell's bib. It really looks simple & easy to make. Like cjsews said in her post above, you could just fold up the bottom for a pocket or just make a simple attached pocket to the front.
https://www.youtube.com/watch?v=AykM4BGpnoA
P.S. Just another thought after watching Rob's video....you could make a separate bean bag for the pellets & put a piece of velcro on the back side of the bean bag & a piece of velcro on the tabs of the bib. That way you could just pull off the bean bags when you got ready to wash the bib. Hope this makes sense.