軟硬不吃 immune to both soft and hard tactics [cajolery and coercion]; neither enticed by the carrot nor brow-beaten by the stick; neither listen to reason nor bow to force; yield to neither the carrot nor the club [stick]
軟硬兼施 act tough and talk soft; adopt every possible means, tough and soft; bring both force and reason to bear; combine hard tactics with soft; combine harsh and mild measures; couple threats with promises; resort to [use] both the hard and the soft way; temper force with mercy; threaten and entreat by turns; try both tough and soft tactics to ...; use all tactics, both soft and tough; use [resort to] both coercion and persuasion; what by [with] coaxing, and what by [with] threatening, (he ...); wield both the carrot and the stick