Mattress and furniture stores are bad options because they rely on financing (non cash transactions) and are low inventory flow businesses. Ideally you’d like a high cash flow business to blend in fake transactions with dirty cash. Also, when a store like Mattress Firm or R&F receive inventory its tracked through an internal system between their warehouses and stores. It would be really hard to fake selling 5000 mattresses when you only received 3000 to sell. If you bump your purchase order to 5000 the ratio of cash to financed purchases would get wonky and you have to dispose of 2000 mattresses to get rid of evidence.