iFKA You have got to get the diva cup (or keeper or moon cup...). Please search for those threads and learn all about them. Or go to divacup.com and keeper.com

Menstrual fluid rinses out of the chamois surprisingly easily. So even if you can't officially wash, can you just rinse your shorts in the evening? Either way I would avoid using a liner. There is no way re-using a liner is more hygienic than just re-using shorts. And you are opening up yourself to the possibility of chafing.

Your trips sound like fun! I think I'm too old and spoiled to really rough-it anymore.