Not OP, but I think "financial heroin" in this context is any kind of loan or debt, being advertised and sold like a fancy product.
Ex: At Apple stores, the associates tell you This new iPhone X is just 33$ a month, and then I ask them "But it's 1000$ though, so I'll be paying 33$ / month for 3 years?" and they say "Yes."
Also credit cards are advertized so much but every credit card charge that you incur swiping the plastic is a loan you take from the company for the amount you are charging on the card. Lot of people don't realize this..
