miss janet–great idea! definately i would second the bandana idea.
i would say try starting “miss janet brand hiking materials” or “trail rated by miss janet” or “miss janet’s comfort wear” or something of that nature. so even if its just ordinary socks or something, they can have your tag sewn into it. especially if you come up with a small decal, like a silhouette of your house or your great smiling face that would be your brand emblem.
also–perhaps car decals? something that when the hiker gets back and gets their job they can stick proudly on their car to advertise the great time they had at your hostel.
shot glasses? maybe not the image you want to spread.
shower shoes? um underwear? seems like everyone wants fashion underwear/boxers/bikinis/other types of womens underwear. dog snacks? sunglasses? what about selling your own trail foods/snacks–making your own dried apples/bananas/etc. anyway. just some ideas that were off the top of my head.
ohh-- maybe souvenier pencils and pens . people need em for their journals.
big boy