Above, I've shown how I quickly + easily tie a scarf into a useful little container. Tie loose knots in opposite corners, add the treat into the pouch formed, + tie the untied corners together. The scarf takes up almost no space in my bag + could also be used as a napkin, handkerchief, paper towel (after washing hands), or scarf to tie back unruly hair...and I can always tie it around my neck too. :)
About once per week, I wash these used bentos + scarves along with my grocery bulk bags (turned inside out), kitchen towels + washcloths.