Just add water? Chlorhexidine's antimicrobial properties are minimally affected by dilution in saline compared to water.
Vintimilla DR, Chambers L, Mauffrey C, Parry JA. Just add water? Chlorhexidine's antimicrobial properties are minimally affected by dilution in saline compared to water. Eur J Orthop Surg Traumatol. 2020 May; 30(4):613-615.