[Intercourse] How to Prevent or Control Post-Coital Odor

So, my wife and I (in our late 20s), have been going through somewhat of a sexual renaissance. We've been very active lately. Honestly, a lot of it has to do with you incredible people being so willing to share your experiences, tips, advice, etc. Much of what we've read on here, we've likewise employed actively in the bedroom. I'll come home from work and excitedly share, "I read something on the sub today that I think will be really cool!"

Anyway, as part of this renaissance, we've encountered an odd side effect of the constant intercourse: the odiferous nature of stale cum from the prior session's engagement. Now, I don't entirely understand the female anatomy, she laughed when I suggested a quick flushing of the pipes (it was much more innocent of a question than it sounds). She said you can't exactly do that. I, myself, am pretty smell sensitive. I can dig if there's just normal body odor, but we all know the smell I'm talking about. And it obviously, me being smell sensitive, prevents me from fully engaging orally - which is a total bummer because I've been learning a ton about that from this sub.

So aside from douching - God, I don't even know if this is something allowed for the vagina - what can we do to control that odor?

And yes, being a recently "vasectomized" male, I do not employ any preventative measures i.e. condoms, interruptus, etc.

EDIT: The odor is fishy, not BO-y