As long as said memory items do not conflict with the AFM/QRH there's no reason you can't use them. At that point they're just flows, which I'd follow up with the QRH.

As was mentioned, the POI should have signed off on it which would remove any grey area on your part (even if it did conflict with the QRH).

If you're worried about not backing it up with a checklist, then make your own...nothing says a pilot can't refer to his own notes.