Keilim

Question

You state that the reason why it is permitted to use meat utensils for dairy and vice versa (on an occasional basis) is because of the idea that we kasher keilim based on rov tashmisho and the majority use of utensils is in a kli sheini. However, what about ashkenazim who are strict and, according to the Rama, will perform hagalah on a keli even if it was only used in a kli rishon once? (Does your father not endorse this minhag?)