Haven't used the scentball yet, but I'm a repeat customer for their spray scents & "Big Paw" paste attractant. The spray scents are VERY potent and can be smelled by a human nearly a hundred yards downwind from the baitsite (& I suspect much further by a bear).
The "Big Paw" paste can be smeared on stumps & tree trunks around your baitsite, much as you would do with cooking grease or molasses, which is how I use it. "Big Paw" can also be heated to create a sweet white smoke, much like you would get from doing a honey burn. "Big Paw" contains honey, so don't use it in an area where foodstuff baits are prohibited.
Brad (from BearScents) informed me that the scentballs contain the same scents as the liquid sprays, in a concentrated form. I suspect they should work equally as well, particular in areas where you are not able to replenish bait on a daily basis.