Maun is the gateway to the Okavango Delta, and the airport there primarily serves the 'high end' tourist market. You could be forgiven for not realising this given the disgraceful state of the ladies' toilets (in the interests of gender sensitivity, I didn't check out the gents, but am told that they are no better).
An international airport is the gateway to a country and creates the first impression in the mind of a visitor - in this case, one of neglect and disinterest in maintaining even basic standards.
At the time of my visit (November 2009), the ladies' toilet in both the arrivals and departure areas were in a state of disrepair. Toilets did not flush, taps did not work, sinks were hanging off the wall and it was clear that there had been no repair, let alone maintenance of these facilities in a very long time. They were also less than clean and both toilet paper and soap were in short supply.
I have travelled a lot in Africa, and have come to expect very little from the amenities in airports and other public buildings. One can understand that poor countries might not have the financial resources available for repair - but even then, one would at least expect the operators to have some pride and ensure that even where the facility is rundown, the toilets are at least clean (as is indeed the case in somewhere like neighbouring Zimbabwe).
However, Botswana is a relatively rich country, the Okavango is a 'high end' destination, and Maun caters primarily for luxury tourists who are entitled to expect high standards because they're paying top dollar. I estimate that upgrading the toilets in the entire airport would cost less than US$100,000, which is a drop in the ocean compared to the revenue generated by tourists to the Okavango. Sadly, this does not seem to be a priority for the Botswanan authorities, and my attempts to constructively feed back on this issue have been pointedly ignored.
Unfortunately, one has little choice but to use the facilities available. My advice is to make sure that you plan for the worst: if they have done something about upgrading the facilities, you'll be pleasantly surprised, and if not, at least you'll be prepared! In the latter case, perhaps provide feedback through your travel agents and the tourists authorities, and perhaps eventually the Powers That Be will get the message and be embarrassed into action?
Motor boats are not permitted within the Okavango Delta. As a result, the only real for of transport that will enable you to see this area, (apart from a plane or helicoptor,) is the mokoro.
The mokoro is a dug-out canoe made from a large straight tree such as a sausage tree or an ebony tree. It is ideally suited as transport in the delta as in can move quietly through shallow water, being pushed by the boatman using a long pole, moving along the narrow channels or cutting through the long grasses or papyrus.