Customer's invoices paid by another customer?

[Luke <..hidden..>]

Accounting question.

I have a customer with several years of outstanding invoices.  They are 
about to be paid, but another customer is going to do the paying.

I am looking for the best way to record and track this.

The process discovered earlier this year for handling employee expensed 
vendor purchases in LedgerSMB, should work in reverse for this I think.

That process was:

0.  Create two vendors: real and employee.
1.  Bill real vendor.
2.  Pay from a liability bank account.
3.  Pay the employee from the real bank (asset) account, balancing against 
an AP clearing account (liability), via cash -> payments [all].
4.  Transfer from the AP clearing account (liability) to that liability 
bank account to balance the books.

I am thinking that the mirror image of this process would be:

0.  Create two customers: original and payer.
1.  Bill the original customer.
2.  Receive payment to a fake asset bank account.
3.  Receive a payment from the paying customer to the actual asset 
account, balancing against an AR clearing account (asset), via cash -> 
receipt [all].
4.  Transfer from the fake asset bank account, to the AR clearing asset 
account, to balance the books.

Do I have this right?

The order of steps 3 and 4 on both of these probably don't matter much.

Luke