I haven't personally heard of it, but if the fillers ARE the cause and not the bromine....Brilliance has bromine granules (and a dispenser with a mesh sleeve). We use it, it seems to work very well, but then, I don't know if I'd be sensitive to the walmart stuff.....
Brilliance Sanitizer:
Active ingredients: 1, 3-dibromo-5, 5-dimethylhydantoin
Available percentage: 99.4%
Online they show "Leisure Time" products, but at our super-duper-huge-WallyWorld, that's not what they sell....go figure.
Best of luck!