Reddit mentions of Ultrathon Insect Repellent Lotion with up to 12 Hours of Time Release Protection (Pack of 3)

The hikes are perfectly doable for the majority of fitness levels. It's not something I would take my grandparents to, but I think anyone in moderate shape will be just fine. The hardest part is the heat and humidity, so make sure you stay hydrated. Other than that, it's really just watching were you step so you don't trip over roots or sink your boots into mud. In terms of the specific tour you will be going on, I cannot give you details about the activities and how exhausting the days might be, because I'm not your tour guide and I don't know where you will be staying. Every lodge and every tour is different. You will need to reach out to the person actually running your tour to get those details. If you have any say in what you get to do, request that you go out in a canoe one night to listen to the insects and see the stars. It's absolutely breathtaking.

I brought two light weight long sleeved shirts and two pairs of long pants. If you're trying to pack light, one of each would be fine, though I appreciated being able to wear something that wasn't super sweaty (although my clothing was all quick dry). Unless you're rolling around in the ground after it rains, I don't know why you would get any more mud on you than a regular hike. This also goes to your question about shoes - most lodges will provide you with rubber boots to wear during the hikes on land (that's how easy they are - you can do it wearing rubber fisherman's boots), and you tuck your pants into the boots. That way you just hose the boots off at the end and you're good to go.

I personally bought the insect repellent on Amazon, because my travel doctor recommended a specific kind and that's where I was able to find it. If you're able to find something to treat your clothing with in your local market, then you can buy it there. If you can't find it in person, by it online. You need to treat your clothes before you travel, and you leave them outside for a few hours to dry prior to packing. I used this for my clothing and this is the lotion I brought with me for my skin.

Buy one of those face net thingies. As for repellent, we tried three or four products, and the only stuff that seemed to work was Ultrathon Insect Repellent, 12 hr time release. Even in areas where we were being swarmed, this seemed to mostly keep them off the skin.

Bring more than you think you need.
https://www.amazon.com/Ultrathon-Insect-Repellent-Cream-Pack/dp/B00KXB3QWU