Place into cash-based businesses with minimal consumables tracking (nail salons, hairdressers, laundromats, service based businesses in general); layer via vendors to those businesses (invoicing for product they don't receive, or just marking up product they do get to premium prices), integration by dividend/partnership payouts to individuals, or other commercial transactions to other businesses. (Really, now that layering happens inside the USA to avoid bulk currency smuggling detection, and happens in businesses vs. cambios, layer/place/integrate is a much fuzzier distinction than it was in the 1980s. It's basically "get physical cash plausibly into a till" and then cycle it.
This might sound crazy and naive but this sounds like the most ripe area of cyber fraud: creating an ap/series of apps (inventory, sales, POS, etc) that supports this type of fraud...
They already exist... on the industrial scale. Which is where the rumored Wachovia laundering of mexican drug money was really active...
Yes, selling "licenses" which can be transferred, redeemed, and re-used is pretty plausible. However, your average Mexican cartel leader doesn't understand software, and is going to be a lot more comfortable with a sketchy mundane business where he can physically see it and understand it.
Cellphone stores are often used for this, I think, though.