I cant find a similar product EU right now .... but the active ingredient in that ZEP seems to be this
https://en.wikipedia.org/wiki/Sodium_dichloroisocyanurateI see it in tablet form on various sites mainly for use in swiming pool ( is that the stuff thata used to burn your eyes ) perhaps pools use less now , my school swiming pool used to choke and blind us
The other ingredient used in other laundry chlorine products seems to be sodium hypochlorite , thats the stuff the guys use to clean paving ,patios etc so you might find it in you town in a hardware or cleaning supplies store .
One thing though , is the main purpose using chlorine in iran to adjust the bright dyes to a shade they perfer ? that might not be desirable in the cleaning process ? ok if they have white , but the reds and other colours may fade a bit ?
is it possible there is confusion between a ' finishing wash ' which the iranians do towards the end of the rug making process ... and a cleaning wash , like you do aaafter the rug has beeen used .