Must have worked.
I used these drops as a final step after filtering the "frogs and logs" out with the MSR Hyperflow. While the drops are technically only part of the SweetWater system, I can't imagine why they wouldn't work with the Hyperflow. They are quick (5 minutes), lightweight, and produce no trash unlike the individually-wrapped tablets that can take up to 4-hours to treat water. They do leave a chlorine-taste to the water, but it isn't too bad and seems to lessen the longer you let it sit. We used them to filter water for a 6-day trip, and didn't get sick, so again, they must have worked. The convenience and ease of use make them worth twice the $10.