Yes, I agree that aerating the D-Box directly is a superior project. A 4 inch long x 1 inch square airstone such as used in an aquarium would be perfect for the D-Box, I have one on order from Amazon.Com for my own D-Box.
You can order aerobic anaerobes here:
Young Tank Tablets This 3-gram tablet contains 60 billion microbes -- a consortium of 100 species of aerobic, micro-aerobic and facultative anaerobes of the Archaea domain. The Tank Tablets are packaged as either 10 or 24 tablets in a clear, easy-to-dispense tube. http://www.young-enterprises.com/products.html