It would also have forced the Government to spend hundreds of millions of pounds remodelling, or even rebuilding, a handful of surviving Victorian prisons to ensure that every cell has its own lavatory.
Although slopping out was phased out in the 1990s, it is still used in some cases.
At HMP Albany, although prisoners do not have individual lavatories, there is a system in place to enable them out one at a time to use communal facilities even during hours when they are confined to their cells if they do not wish to use a bucket.
Mr Justice Hickinbottom dismissed their claims after a costly two-week High Court hearing last December.
But yesterday Hugh Southey QC, for Grant, argued that developments in European law regarding prison conditions since last year's judgment ought to lead to the High Court ruling now being overturned.
But Lord Justice Davis, sitting with Mr Justice Treacy, issued a withering rebuff, deploring the fact that the English courts had been compelled to hear the prisoner's "exaggerated" complaints at all.
"It is more or less unthinkable that an action of this kind could have troubled this court, even a few years ago," he said.
"But the European Convention on Human Rights has changed that.
"This case has occupied the time of a High Court judge and, notwithstanding his detailed judgment, this case is now the subject of an application for permission to appeal.
"The core substance of this application is that any use of a bucket in a cell is a 'no-go area' and is unacceptable, absent only specific security considerations."
He went on: "Mr Justice Hickinbottom in the High Court rejected much of Mr Grant's own evidence as false or exaggerated.
"Aspects read as if HMP Albany is a prison with no running water or toilet facilities at all and as if slopping out is the only way prisoners can deal with their bodily functions.
"That is a travesty. There is ample access during the day to washing and toilet facilities.
"The prisoners were in single cells, they were of a proper size and adequately lit and ventilated.
"Air fresheners were provided in case the need to urinate or defecate should arise."
Dismissing the relevance of the European cases, he added: "There is a certain sensitivity to feelings of degradation attached to the status of being subject to forced incarceration.
"But that doesn't mean that unreality needs to descend into this area.
"The use of a bucket in a cell as a back up to the other entirely adequate sanitary facilities available doesn't even begin to constitute inhuman or degrading treatment."
