Chemiclean is an antibiotic, erythromycin, despite misleading claims otherwise.
We always suspected it was erythromycin because of the very strange wording that it was not "erythromycin succinate:". Sort of like saying you don't have a red car when asked if you have a car.
But apparently a government office in Germany tested it and found it was erythromycin:
http://www.ultimatereef.net/forums/archive/index.php/t-526917.html