Why On SSB phone, the accepted way to join an ongoing QSO is to wait for a natural pause between transmissions and simply give your call sign once, clearly. That identifies you legally and lets the stations in contact decide whether to invite you in. Repeating it over and over or using CB-style jargon just clutters the frequency and wastes time.
Watch out "QRZ" is the Q signal meaning "who is calling me?" and is used by a station that has heard an unidentified caller, not by the station trying to break in; "CQ" is a general call to anyone, which is not what you are doing when two stations are already talking.
Break in with your call sign once, not twice, not "breaker breaker." Amateur radio is not CB.