hey guys,
Aerators definatly do work to eliminate bottom muck in the pond. I instaled 6 Vertex diffusers into my 8 acre lake and in a couple months places that had once been 4 inches of slimy, stinky goo were nice sandy bottoms. as far commercal bacteria I'm not sure because I've never used any but I have heard good things. But they do more than just "eat" muck they also do alot to improving water qualities mostly with 2 important types of bacterias.
1. bacteria from the genus nitrosanomas convert ammonia(a very toxic chemical) to nitrite (a semi-toxic chemical)
2. bacteria from the genus nitrobacter convert nitrite into nitrate (a non-toxic chemical that is usefull to planktonic algea)
Now obviously any pond that survives has both of these naturaly but as to wich specific species I can't tell you and it would vary anyways between brands.

Take great care of it, or let someone else have it.