Whatever the vehicle type common problems arise from the factor common to both which is the lack of room for a loo.
Now, two other factors come into play. What form of camping generally is undertaken and with whom.
I am mostly a solo traveller so I have no need to worry about the sensitivities of anyone else when getting up for that middle of the night excursion.
I also spend a lot of time either wild camping or camping in places where there are no facilities. In those circumstances on board facilities are a must.
So now it comes down to type of facility.
My first preferment was for a thetford 335. Everything contained in it's own chemically sanitised environment. However whether beach or ocean it still takes up a large chunk of space. This results from the design of the cali itself with a rear seat on rails offering the maximum of flexibility regarding type of use but limiting in that a large rear space, which in other conversions is often used for toilet facilities, is otherwise taken up.
Another disadvantage of the thetford, regardless of whether beach or ocean, is that it must be emptied, and when in constant 24 hour use that must is a fairly frequent one. If anyone has ever experienced a 3 day or more trip into the wilds then you will understand just how inconvenient that could be. I have less than fond memories of swallowing my discomfort and walking into a pub to ask if it was possible for me to use his loo's to dispose of my waste. A most unpleasant but necessary recourse.
So I now use a bog in the bag. This also has disadvantages. The first is placing one's waste into public bins. However I do that all the time for my Grandchildren, disposable nappies, what Millions of mum's use everyday.
The Second is the prohibitive cost of the bags. I use disposable nappy liners, and before anyone screams "landfill" I use the relatively expensive compostable ones, environmentally friendly and when compared to bog in bags inexpensive, and I use AllBio plant resin 25l bags as the receptacle, also environmentally friendly and also comparatively inexpensive.
A number of advantages, whether beach or ocean. The size is minimal when rolled up: The waste can be stored in other parts of the van (another, larger all bio bag with Milton spray) until convenient to dispose, disposal points (rubbish bins) are easier to find than CDP's, quick to put up and unobtrusive when down and, just like my old 335, can be used as a handy stool.
If none of these suit then I suggest two alternatives:
I: Use all facility sites and park as close to the facilities as possible (the last three days at Cirencester park I had no more than a 20 metre walk).
2: Bin the cali and get a conversion that sacrifices the convenience of a rear bench on rails for rear space that can be converted to an on-board bog. Just don't expect to have the convenience of using the cali as a removal van, tyre store or cycle transport without buying a cycle rack.