It seems like you could do the “final check” of the word(s) they are working on right before you dictate, whenever the student is ready.
“He lets his teacher know when he is ready. The teacher asks if there are any words he is not sure of. These she puts, one by one, on the blackboard, letting the child look till he has a picture, and then rubbing the word out. If anyone is still doubtful he should be called to put the word he is not sure of on the board, the teacher watching to rub out the word when a wrong letter begins to appear, and again helping the child to get a mental picture. Then the teacher gives out the dictation, clause by clause, each clause repeated once.” (Vol. 1, p. 242)