Rinse well after your stop. then half way though the bleach at the specifed time, under dim incandescant lighting, take a look at the bleaching action on the film. Is there silver image left or not?
If not, then consider extending the time as required to fully bleach.

Recall that this is before the fix, so the film will naturally be milky.

Regeneration can be as simple as a tropical fish tank air pump, short bit of air line and bubble stone - leave it to fizz into the bleach for overnight, and see if the bleach has more oomph the next run. Make careful note of volume before aerating, and replenish any evaportated water befoe re use, or you risk being short of solution to fully cover the top reel.