Stroop effects can be modulated by context-specific cues associated with different levels of proportion congruent, even for items that appear equally frequently in each context. This result has important theoretical implications, because it rules out frequency-driven learning explanations of context-specific proportion congruent (CSPC) effects and leaves open the possibility that a cue-driven retrieval process can reinstate attentional control settings in a rapid online fashion. The purpose of the present work was to address reproducibility concerns that have been raised about this finding. We conducted several reproductions and novel extensions using Amazon's mechanical Turk in both Stroop and flanker tasks. We successfully replicated the central finding that CSPC effects can be observed for frequency-unbiased items. We also provide new Monte Carlo simulation analyses to estimate reproducibility of the phenomena that show important limitations on these designs for measuring contextual control.