This hodgepodge was referring to trying to schedule employees for their time off. It is a mashup of “throw a (monkey) wrench into the works” (disrupt or foil a plan) and “iron out the kinks” (fixing small problems that are present in a project). The idiom “throw a monkey wrench into the works” seems to be a difficult one for many to say correctly. It has been the subject of prior malaphors, e.g., “a wrench had been thrown in the bucket” https://malaphors.com/2016/10/04/a-wrench-had-been-thrown-into-the-bucket/ and “he really threw a monkey wrench into that fire” https://malaphors.com/2013/02/08/he-really-threw-a-monkey-wrench-into-that-fire/. Not sure why, but my guess it’s a rather archaic saying. A big thanks to Dori Shand Riley for hearing this one!