Effective helical twisting powers of a number of enantiomers and achiral conformers were measured in highly twisted cholesteric phases varying in both chemical composition and macroscopic chirality. In certain solute-solvent combinations, and particularly in steroidal solvents, pronounced non-symmetric effects of enantiomers and conformers were observed on right- and left-handed cholesterics. Achiral rod-like solutes, which can exist in different conformations, were found to behave as though they have a left-handed helical twisting power in both right- and left-handed short pitch steroidal cholesterics. All effects can be interpreted as being due to specific short range molecule-molecule interactions. No evidence was found that the macroscopic chirality of a cholesteric medium can influence the conformation of an achiral solute.