The red tape Super PACs get around concerns how much money can be received. While a presidential campaign can only receive $3,300 from an individual, and a traditional PAC can receive up to $5,000, a Super PAC can receive unlimited donations from both individuals and corporations. That’s the money laundering part - it allows the super rich to put unlimited money toward a political cause even though the system was originally designed to prevent this.
But the official name for Super PACs is “Independent-expenditure-only political committee”. So, while they are allowed to receive unlimited funds, they cannot give it to a campaign or do any spending in coordination with a campaign (though how many Super PACs strictly follow the no coordination rule is hard to quantify).
Essentially, the DNC giving the money to a Super PAC would be similar to if they kept the money and did the independent political expenditures themselves. The difference being that they would lose control over what independent expenditures the money goes towards.