Gordon's suggestion is very valid.
I am one of the folks who is very pleased with my C-head composting toilet. To be honest, these are actually dehydrating toilets. They dry the solid waste, and separate the liquid. Once the solid waste is covered, and the outside is dried, there is no odor. Think dog poop in the yard. If it has been in the sun for a few hours and the outside is dry - no odor. If you happen to step in it and expose the inside (moist) part - WHEW!!!! The liquid does need to be emptied regularly, but this is very easy.
I installed a C-head in my 13 foot Scamp
and loved it. When I ordered my new 16 foot Scamp
, I had them leave the toilet out and planned to transfer my C-head. However, when the folks bought my old Scamp
, they convinced me to leave the C-head in - they loved the look and idea of it.
I had to buy a new one for my new Scamp. I have been using them for about three or four years now. I travel to Florida every winter for several months. In the four years, I have only had to empty the solids one time while on the trips. I normally wait until I am back home to empty it. The one time I had to empty before I got home was due to a fly infestation. I could have treated it with a no-pest strip as the manufacturer suggested, but I chose to just empty the solids and put in fresh medium - problem solved and has not returned.
The advantages you state are correct, much less frequent emptying (other than urine, which is very easy, virtually no odor, no water use. I do bring my solids home to actually compost in my yard - just keep a separate compost pile for non-edible plants. This is recommended if you want to be 100% confident you are not contaminating your garden. Many folks find this is not necessary to worry about. Most folks discard the solids in a dumpster. Personal choice.
I travel alone, and I only use the C-head for emergencies and night time deposits. If you use it all the time, or have more people using it, obviously it will need to be emptied more often, but probably not more than every two weeks. Also, it can be emptied right in your campsite, no need to pack up and move to a dump station.
Now, all this said, there are a few drawbacks:
One, they do not handle vomit or watery stool very well. If either of these are a problem, most recommend lining the toilet bowl with plastic bags and disposing immediately until the problem resolves.
Two, if you have multiple people using it, you may need to install the included ventilation kit. I do not need to bother with that.
Third, while the toilet will work if you deposit the toilet paper into the solid waste receptacle, it will remain visible and will cause the toilet to fill and need emptying more quickly. Most folks choose to keep a separate container in the bathroom to deposit the toilet paper in, then empty it into the trash every day or two. Not really all that big of problem.
As I said, I am 100% sold
on the convenience and efficiency of a "composting" toilet. Just make sure you get (or make) one that separates liquids from solids. Mixing of solids and liquids is what creates sewage and causes the ongoing odors.
My C-head is a simple design and very effective. Plus it is the cheapest of the commercially available products. Also, it fits very well in both the standard front bath or the side bath of the Scamps.
Hope this helps you sort it all out.