Certain people benefit from using an oral rinse that’s stronger than the typical store-bought mouthwash. The most common rinse is chlorhexidine , also known as chlorhexidine gluconate  (CHG), which is available in both prescription and non-prescription strengths. This is the same antibacterial agent applied to the skin just prior to surgery. While effective at reducing oral bacteria, chlorhexidine does have a measure of toxicity and is not without side effects, including impaired taste, swelling of the tongue, dry mouth and tooth staining. Anaphylactic reactions have also been reported. 

For intubated patients in hospital intensive care units, decreasing the risk of Ventilator-Associated Pneumonia (VAP) is of particular importance. Between April 2014 and October 2014, Iranian researchers observed the effects of treatment with an echinacea mouthwash compared to chlorhexidine in 70 patients aged between18 and 65. The study subjects were randomly assigned to one of two groups – 35 were assigned to the intervention group and 35 to the control group. Both groups achieved decreased microbial flora with treatment with either 5 mL of either 0.01% echinacea or 0.2% chlorhexidine mouthwash. However, after four days, the intervention group given an echinacea mouthwash experienced a larger decrease in microbial flora than those in the control group.

It isn’t clear what species of echinacea was used or exactly how the mouthwash was made beyond infusing an unspecified amount of the dried herb in water for 60 hours, following by filtering.

Reference

Safarabadi M, Ghaznavi-Rad E, Pakniyat A, Rezaie K, Jadidi A. Comparing the effect of echinacea and chlorhexidine mouthwash on the microbial flora of intubated patients admitted to the intensive care unit. Iran J Nurs Midwifery Res. November-December 2017;22(6):481-485. doi: 10.4103/ijnmr.IJNMR_92_16.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5684798/