Is washing the genitalia with dettol a good idea? I am a 22 yr old female and have been doing this as it itches uncontrollably.

No! ↑es vaginitis. A crucial part of immune system strategy for preventing skin/mucous membrane problems is favoring growth of bacteria which out-compete other potentially harmful organisms. There is little evidence that antibacterial agents promoted to the public have any benefit over soap & water; indeed often ? problems. This is especially true for vaginal/labial tissues in which lactobacilli prevent pathogens.