Bromide/bromine can not be stabilized against sunlight. If you don't add massive amounts of chlorine afterwards at the right times you won't have any sanitizer in the pool at all and can easily have the algae come right back and be even more difficult to fight because the bromide/bromine will keep using up all your chlorine until it goes away.
This whole approach is only worth it when CYA levels are extremely high. The reason it works so well when CYA is high is because bromine is not affected by CYA the way chlorine is, so the bromine is "full" strength, while the chlorine is buffered and less effective because of the CYA. At normal CYA levels, there is no point in doing this, since chlorine alone is plenty effective enough. At normal CYA levels, you can get the same effect for less money with chlorine alone.
In the specific topic you originally suggested this in, it is even less appropriate. The pool was already clearing up, so the algae was already dead, or nearly all dead. It would be like using a stick of dynamite to knock over a wooden wall that was already rotted through so thoroughly that you could push it over with a finger, a waste of time and dangerous to boot.
