Polishing hazy/dull natural stone beads for jewelry making?

I don't know if keeping the beads on the plastic string would work. I would guess it will make most areas of the beads not properly polished?

If you are tumbling the beads alone, you better fill the holes with wax or something else. Lessons learned in a hard way.

If your goal is just to improve the polish on the beads-then you could try just running matching mohs hardness beads in *dry* corn cob media with some good quality polish...however, rotary polish is likely to be uneven if the movement is tangled with a string.

Without separating the beads:  dry polishing in a vibe tumbler would be ideal for your intent. 

How big are the holes? I don’t think they would plug with grit. The edges of the holes will get a little rounder and less sharp

If I were to try it again, I would still remove the beads from the string, keeping them on the string will cause them to get more oval shaped. No need to fill the holes in my opinion, even at 1.5mm mine stayed clean even through the 12,000 grit cycle.  

I would then skip the rotary tumbler using only my vibratory, but that's a sizable expense if you don't already have one...   I did the ones in the post above with Silicon Carbide at 500 grit & 1500 grit in my rotary, then because of the haze, I put them back in at 220 > 500 > 1500, finally moving to a vibratory with the 12,000 grit Aluminum Oxide.  I would also use a lot of 10mm round ceramic sphere's as filler media (this might help the rotary tumbler get better results), and buy my beads from a better known company.

You might also want to get an ultrasonic cleaner just in case you do get some grit stuck in the holes.  There is a chance that smaller holes could get packed with slurry, an ultrasonic cleaner cleans out grit from pockets, cracks, & holes pretty easily. Vevor makes a 650ml ultrasonic jewelry cleaner for about $30 that would be perfect for cleaning beads after polishing.  

BTW... that gem foam is basically a filler material that is only intended for use in the polishing stage. Because it's porous, grit will get embedded in it. This makes it work like a felt polishing pad where you would add your polish to the felt and polish by hand. Also, it only works in a rotary tumbler, if you put it in a vibratory, it will get stuck to the side of tumbler and get pushed up above the rocks.

Welcome from Southern Nevada.

Yeah, money is a bit tight right now, so unfortunately getting another tumbler isn't really an option. :-( I also don't know if I'd use a vibratory one all that much.

Oh no, I'm so sorry! I'd be worried that might happen to mine, as I got them all off Temu...

Corn Cob is better for polishing than the plastic pellets.  Plastic pellets are a filler material, and while grit will stick to it, it doesn't really hold grit as well as corn cob does.   

You could also use ground walnut shell instead, which is around $29 for a 25lb box at Harbor Freight, if you have one nearby.  In terms of hardness, walnut shell and corn cob are the same for untreated media - 2.5 on the mohs scale. I think the corn cob is a little better at holding onto polish than walnut in my opinion, though both are much better than plastic pellets.  

The corn cob that I've seen at feed stores is normally for small pet bedding and doesn't get graded(sized), it may also contain straw, grass, small twigs, and other foreign materials in it from time to time.  Because it's ungraded, it will range in size from coarse powder (like fine corn meal) to about 3/16" chunks from what I've seen.   BUT, if you buy a large bag of it, you can get it for less than $0.50 per pound & sometimes as low as about $17 for a 50lb bag, compared to graded corn cob media which is usually anywhere from $1.70 to $10 per pound.  

That said, Frankford Arsenal untreated corn cob media 15lb bag is currently on sale for about $16 shipped for prime members - I just ordered another bag!