Depth charges by total kills, Hedgehog by wartime effect

What was the most effective anti-submarine weapon of World War II?

Depth charges probably led by raw number of kills, but Hedgehog may have been more effective across the period it was available.

Depth charges lead numerically because they were widely used throughout the war. Hedgehog qualifies that result, whose ahead-throwing attack offered major tactical advantages despite entering the contest later. The comparison depends on whether a weapon is judged by lifetime totals, per-attack performance, or operational influence.