Although I understand that smurfing is the process of breaking money into several smaller transactions, the article you mentioned mostly refers it to money laundering. We aren't talking about money laundering in what I'm referring, we're talking about selling goods, with the appropriate invoice, but split into two in order to be able to accept cash. From my perspective, it sounds a little overexaggerated.
Are you sure? My country also has a 'smurfing' law and while it does fall part of a larger Anti Money Laundering law, it does not necessarily relate to Money Laundering itself. Basically, splitting a larger transaction that exceeds the maximum cash limit into multiple payments to overcome the limit is an Anti Money Laundering regulation.
You can sell cookies or even mow the lawn of your neighbor. If the total payment exceeds the limit and you split it in multiple parts so the other party can pay in cash, even if the cash came directly from an ATM salary withdrawal with all proof it still falls under the same article of the law. Anti Money Laundering measures.While I do not condone what the governments do at all, it is worth knowing the truth here. I doubt the Greek government did not have a few measures implemented particularly to block attempts at bypassing the law.
The owner of the business you worked at may have asked you to do something illegal for your customers.