I've been using this portable bidet at least once daily for around 5 months and find it very convenient. Much cheaper and less time consuming than showering twice a day.
I use only around 1 inch (2.5cm) of water which makes it easy to fill and fit in position. If carrying a basin of water is a problem then it could easily be positioned then filled to a level of 1" with 2 pints (1 litre) using a jug.
I don't use soap, but instead use Dermol 500 lotion, a soap substitute. 500ml of this lotion lasts me around 4 months but I use it to shower, too. If I used it solely for bathing using this bidet then I think it would last me well over a year.
I have 3 toilets of various sizes in my house and this bidet can be used in all of them.
Worth every penny and more!