An update on "indoor" facilities:
For two years I have been using a thetford 335. Sometimes the bulk space when carried inside the van has been an irritant. Thanks to my thetford being "borrowed" for one of my Grandchildren's use, I had to resort to a bog-in-a-bag for this weekend.
I have been quite surprised at how easy to use it is. The main use for me is both when travelling, especially in remote areas, and overnight when not wanting to pop out of the van.
To stop, erect the tripod "seat", pop in a bag, use, pop out the bag, is very easy, very quick.
Overnight to open it up, pop in a bag, and leave erected, just like the thetford it fits neatly at the end of the extended bed.
Disposing of the bags is easy. Just dispose as you would any other bag of general waste. Do avoid the temptation to recycle
So, big drawback, price of the bags. I used my vast stock of popaloo bags, which when bought from the club shop in bulk, work out at just under £1 a bag. Bog-in-a-bag bags can be bought for a similar price on Amazon if buying in quantities of 25. Therefore the cost factor per use is a lot lot higher than a 335.
so, to summarise:
Pro's: Cheaper initial outlay, Massive space saving, easy to use, convenient disposal of waste or storage until convenient.
Cons: Cost of bags. I estimated that the price difference between b-i-a-b and a 335 initially is about £60 which at £1 a bag is soon made up.
Further research: As a granny I am of course familiar with the efficiency of disposable nappies. So my next line of research will be: Take a bag, replace absorbent granules with disposable nappy, use cheaper "bin liner" bags of suitable strength, insert nappy into bag, use, dispose. I can see an immediate drawback i just the size of bags of nappies but hey-ho, nuclear fission wasn't discovered in a day!
I expect to be publishing my research paper on this line around 07/2016.