Vigorous shaking for HFR interrupted mating
I remember doing this experiment many years ago in an undergraduate practical where we used vigorous vortexing of culture samples in glass tubes to achieve interruption and separation.

According to Griffiths AJF, Gelbart WM, Miller JH, et al. Modern Genetic Analysis. Bacterial Conjugation:


  ... sampling is accomplished by using a kitchen blender to separate
  the joined cells, resulting in interrupted conjugation.