I picked up trash along VDLP on a stretch where it all of a sudden materialise. Bottles of sunscreen, yogourt cardboard, plastic water bottles. Had a grocery store plastic bag filled in a metter of minutes, and that was while not picking up the large 1.5l water bottles.
I am thinking that mojones should be shapped as garbage cans, or simply put garbage cans out there as mojones.
And what about using those backpacks as marketing billboards, but sewing patches that remind people to pick up their trash?
Encourage albergues to put the plastic nags we leave behing after shopping by the frontdoor with a sign asking people to use them to pick up as they walk. 1 bag each per day wouldmake such a difference. Or ise the crendencial as a way to spread the word: mail/hand them out with a few thin plastic bags in them. Make those bags high vis yellow so people see you using them and are encouraged to do the same.
Or, being evil here, only give access to a bed in exchange for a bag of trash.