Continuing with this, I have 3 questions...
1. Can a friend in the U.S. create the WU account in his name BUT send you the money with a debit card that is not in his name? ie YOUR debit card?
2. If not, what about if he uses one of those prepaid debit cards that dont have names on it? Does that work?
3. If neither works then...if you have to send to yourself does AFIP actually see the sender name? Or they just see the sender as WU?
Assuming the answers to the first two questions are no, you could send your friend the funds and he/she coud send the cash from a Western Union agency in the USA to a Western Union agency in Argentina for you to pick up in person.
When sending funds from the USA for pick up or deposit to a bank in Argentina, the sender does not have to have a Western Union acount and neither does the recipient, but the sender must show a valid government issued ID when sending the funds.. Their name will appear in the details of the Western Union transfer which can be "seen" by AFIP (if they ever actuaclly look).
Of course you would need to have a Western Union account to send yourself funds online, even if you pick up the pesos in person. And AFIP will be able to see that you are both the sender and receiver. No matter who makes the transfer, the transfer details will show both the sender and the recipient´s names and AFIP will "have a record" of the transfer.
Perhaps the transfers from yourself to yourself could be made using your US passport number. However, I believe that, as the recipient of more than two transfers, you will be required to fill out an online declaration with your personal information, including your CUIL/CUIT if you have one.
I am not sure what would eventually happen if you do not include your CUIL/CUIT. I daresay this omission would likely arouse suspicions of tax evasion. It might actually be a crime not to include this information. Sending money to a freind in the US to send to you is legal, provided the funds are legally yours, but at some point it might raise suspicions of money laundering as well as tax evasion.
In the near future your friend might not want to deal with receiving more than $600 per month from you via a bank to bank transfer of any kind as the current US administration wants the IRS to soon begin monitoring all bank transactions over $600 and wants to hire more than 50,000 new IRS agents to do so. If they get their wish, nothing would say "audit me" (for tax evasion) more than receiving unreported funds (even if it is not taxable income that must be declared), especially on a regular basis.
If the funds you want to send to yourself by Western Union are not taxable in Argentina, you really shouldn't have anything to worry about.
On the other hand...