I will add my experience. When I bought my PB it was because of dead algae on the bottom of the pool. I had the same experience others have reported of some of it going right through the bag that came with it. Then I purchased from the manufacturer the sand and silt bag which you put inside the one it came with. This worked much better. Since I started BBB and got my original green swamp under control I don't have to deal with the dead algae. But, I do have to deal with dirt. I have fine dirt particles in the form of dust blown in and they settle to the bottom. The PB with the sand and silt bag inserted works great at picking up this dirt. It is the only thing I have found other than the regular pool vacuum that I have found that will pick up the dirt. What it does not do is pick up my leaves. It is strong enough to pick them up, but they get stuck in the small openings. I have a Polaris turtle that takes care of the leaves and I bring out the PB about once a week to get the dirt.
If your filter will catch the dead algae then what you could do is just get the kids in there with the filter running and have them stir it up. If you follow the advice in pool school and here on treating your water you will not have a continual problem with dead algae sinking to the bottom. So once you get it filtered out it should not be happening again.
