I use the Instead cups, which are like the diva cups. They take care of the period stuff.

For the rest, I find I don't have as much normal other stuff if I put a water-based lubricant in my shorts (about a half teaspoon -don't need much - apply directly.) I think sometimes discharge is actually due to chafing or irritation. So when I have the goop in my shorts, I don't have as much personally-made goop.

Also, I handwash my shorts after every ride. Sun dry when possible.