I agree. A clarifier only clumps together particles such that they become heavy enough to fall back to the bottom of the tank. Problem is that the clumps are still there and become breeding grounds for bad bacteria unless addressed.
Clarifiers are best used in unplanted tanks where the person can gravel vacum much of the tank. Then they work great cause you can suck up all the clumps thus removing the harmful stuff.
But if you can't gravel vacum up the stuff then the clarifier will only mask the problem for a short time.
Solution - I'd run a diatom filter for a few hours after your water changes instead of using the clarifier. I think you'll be happy with the results.