Auto Deposit Instruction Program - Do the Ded Per flags work?

We have a need to create a gross up payment for a Christmas Bonus and include it as a separate check during the regular payroll process.  The payroll department wants the $400 Christmas Bonus to only disburse to the Remainder record and the regular pay to all elected deposit accounts.  I thought if I leveraged the Ded Per 1 flag on the non remainder records and changed the flag to N for the pay period the payroll is processing, create the Interim Gross Up, which would create the payment distribution record to only go to the remainder record.  Then change