Bacteria is thriving in your muck. Anaerobic bacteria thrives in the abcense of oxygen and decays organics VERY slowly, while aerobic bacteria thives IN the presense of oxygen and breaks down organics exponentially faster than anaerobic.
If you want to clear the muck rapidly (possibly all this year), spring for the bacteria AND aeration. The bacteria will get rid of the muck, assuming it actually IS organic, and the aeration will not only speed the whole process, but maintain it for many ears to come.
If the "Muck" is actually silt, well................you may need to learn to love playing in the mud!
