As I mentioned in the comments, when I read this question I (and some others) immediately thought of "Chasm City" by Alastair Reynolds. Some aspects do not fit well with the original question however, notably that in Chasm City the bodies were ejected to reduce the mass of the ship and assist its deceleration, while the question dealt with bodies being ejected to cause acceleration.
Reynolds wrote a short story entitled "Night Passage", also set in the Revelation Space universe, which has many features similar to the section described in Chasm City, but seems a better fit. In this story, a sleeper ship gets trapped midway through its interstellar trip by an unexplained phenomenon. The engines are put out of action, and so to escape they jettison cryopods (or "reefersleep caskets" as they are called) using a magnetic launcher. The caskets are visible from the ship, not quite as a "string of pearls" in the original question, but as "brief, bright scintillations":
The flashes continued. Now that I was attuned to their rhythm, I
picked up an almost subliminal nudge in the fabric of the ship,
happening at about the same frequency... Each nudge was the cargo
launcher firing another casket away, the ship's motion reducing by a
tiny value. It produced a negligibly small effect. But put several
thousand negligibly small effects together and they can add up to
This was published in "The Year's Best Science Fiction: 35th Annual Collection" edited by Gardner Dozois, which may accord with one of the OP's comments.