Just use weights so you can clean that bucket/barrel occasionally. Unless you're brewing tea 24/7. Even then, not recommended to potentiate some cultures perpetually. (Random other vectors that can wind up in the soup basically ... rare or hardly noted by many, but it can occur.)
The fishing industry stones come with lead weights on them already. And some of the other ones are just plain massive/heavy. Though I'm not keen on anymore forms of lead than come in various other sources (greensand and the like). I tend to use random stone work laying around that has a hole in it already. Thread over tube, air-stone float not a problem then. Used other nice air devices (and gimmicky crap that comes my way), but I'm a klutz and lean to practical and sterilized OCD land. Figure if I'm going to break em, need to clean them, might as well just cycle cheaper alternatives. Allows my sense of needed protocols for cleanliness and all the rest.
On a side note, the cheaper by the dozen and using multiples on splits per barrel is not a bad way to go in general. Larger barrel runs, add in recirculation pumps with top drop vs adding more air. (Impeller pumps, not bladder pumps for that of course.)
Just food for thought. Otherwise, most air-stones in the glass bead forms wont suffer much from being glued. Lots of fish tank folk do this for reference. But they get the same grief over major tank cleans etc.
Cheers.