I once planned on making large payments on a high interest credit card. I made the decision when I was sober. Then when drunk the money was in my account so I decided to do it right then before I changed my mind.
So I didn't "black out". Simply forgot that I had done it. The next day, I did it again. Bank of America takes a couple of days to process online payments, so noting showed me I had already made the payment.
I remembered that I had done it the first time, when I saw the payment come through twice. Resulting in $380 in NSF fees (my bank will take the large debits first, then charge for each smaller debit, even if it was just a pack of gum). Needless to say, I no longer drank and banked
I also got in the habit of not doing anything while drunk. I'd write myself a note by my computer instead, to do it when I woke up.