you!!!
The menstrual cycle is the reproductive cycle, a domino effect of hormonal changes between the brain and reproductive organs - douching inside your vagina has no effect on your menstrual cycle what-so-ever. Douching is also unhygienic and unhealthy as it can change vaginal pH, force harmful bacteria further into the vagina, and strip vaginal walls of lubrication.
The only difference is the caramel coloring added to brown vinegar. Old Wise tales indicate that white vinegar was used for personal hygiene as in doucing for women and brown vinegar was used for cooking. White vinegar can be used for both.