I put lentils in mine. I leave them in the 1# bags and they fit my Molar very well. When I travel by air I can leave the bagged beans with someone to eat after I'm gone. Shipping peanuts are too light, in addition to being compressible. Some folks like buckwheat hulls because they're lighter than beans. Others use birdseed so they can use it as bait, but you have to protect the bag from rodents then.
Rod, not shipping peanuts. Wait until you arrive at camp and then borrow rice (or beans) and return when you leave and move onto another camp. Don't try and haul the stuff from home. I find no practical differance between beans and rice (unless you eat them). I have also stopped at market when in country bought what I needed and then given them to my guide when I leave. Not good to share a game drive vehicle with someone you have given 10 lbs of beans.
Cheers-Red