Yes, a very muddy hike, challenging and a guide certainly needed. We used Hawaii Bike, but didn't really think much of the guide.
The walk was wonderful though, through interesting and scenic tracks, and a wonderful bamboo forest. The walk took about 50 minutes to the falls. The Waterfall was pretty, but not mindblowing. A very tall, thin, stream of water falls into a small stream. Worth it for the interesting hike. Be aware that you need to be fairly fit to do this hike, as there are rocks, ups and downs, humps and bumps, slippery surfaces and lots of mud to navigate. Those with wonky knees wouldn't manage very well.
Great fun though, recommend it.
No bathroom, make sure you're ...prepared.
Lots and lots of mosquitos, slather or spray on insect repellant, they're ferocious.
It's hot, and steamy. Wear cool clothes and protective footwear, if you're wearing a company's rain boots, take long socks and a spare pair too.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.