Killaroo,
Mouth music and kefuddled, like it.
Oh come on, for goodness sake!! It's not about the CHECK it's about the MOUTH MUSIC. THE CALLOUT. Don't be kefuddled!
Seriously, the check is the thing for sure, but the words (whatever they may be!) serve three key purposes in my mind: communication to the other crewie that the area they cannot see is clear, a trigger for him to also check should he be otherwise distracted and coordination such that more than idle thrust is not commanded and movement attempted until both crew see the area as clear.
Arguably, verbalizing checks probably also increases the likelihood they they are done at all.