You surrendered to raw cock. You said yes to wanting his seed. You were told your fresh-bred pussy was his. Then you tried to flush his seed out of you.
Forgive me, but I don't think you understood the assignment.
If you want to take responsibility for your health get on PrEP and Doxy PEP, both scientifically proven ways to protect yourself when taking raw cock. Not only does anal douching simply not work as a protection from STIs, but there is a great deal of research showing that it makes you *even more* susceptible to STIs like HIV because it increases micro tears in your cunt and removes the healthy and protective anal mucosa.
A breeder put his DNA in your pussy because that's where he wanted it, and what you agreed to. To me, it just doesn't feel respectful to flush him out of you (especially when it doesn't work as an STI prevention measure).