Deleting records often turns out to be a bad idea. Also, what you have there is a calculated table field - also often a bad idea. Getting off of my soap box now...
Methinks if in a Totals query you group by Identity, have SumOfDebit, SumOfCredit, subtract the 2 in another query field and set the criteria as = 0 for that field. Or if you only want to see one particular Identity, add that criteria. Untested and from my coffee starved brain...
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.