You guys have to run to the nearest ABC store and get some Tabi's!!! Go to Hanalei quick cuz!
They are rubber impregnated socks with felt soles, ninja style with the big toe separate from the others. You can RUN with those on, seriously! When I backpacked the island years ago I wore those and even with a full pack I would run full speed through even the snottiest red dirt Na Pali has to offer, past unprepared tourists slipping hither and yon. I learned from a Hawai'ian named Otashi who had two permanent camps on the trail and lived there. Otashi showed me many one trick. I still get 'chicken skin' thinking about them days, and please tell me you've found the wild sweet potato plants, they are bushes, living near the rivers, blueish green ting to the leaves, which are round in nature... look for rounded features where the vines meet the earth. These are the tops of wild, purple, unbelievable potatoes. Wrap them in Ti leaves (ask a local, it's what they wrap the rocks in as offerings at trail heads and what they make the leis out of...) and then put them into the coals of a dieing fire for 1/2 hour or better. Unbelievable.
Also living in the rivers are fresh water lobsters (their eyes glow in flashlights at night) capture them with a stick of bamboo splayed open at the end... really good boiled alongside the potatoes, also, look for fresh water limpits (spelling) stuck on rocks. Hawai'ians call the I'Ivai, or something like that. If you like oysters, you'll LOVE these guys. DANG! If I was there, brothers, I'd show you some magic.
LET'S DEFINITELY SAVE UP OUR $$$
Kaua'i will lift your soul, it is a very spiritual place and regardless of your beliefs will have you paying due reverence to your creator.