Cook, from 1924 to 1941, made his residence at Lake Hopatcong, in Hopatcong, New Jersey, which was then a popular resort. His house was appropriately named "Sleepless Hollow" for the many parties he gave and celebrities he entertained. One visitor, his librettist Donald Ogden Stewart, later recalled that "Joe lived on a mad gag-infested estate in New Jersey which bewilderingly expressed his genius. On his three-hole golf course one drove off confidently into what looked like a fairway only to have one's ball rebound sharply over one's head from a huge rock that had been cunningly camouflaged. The last green was a golfer's paradise in that no matter where the ball landed it rolled obediently into the hole. Conditions inside the house were similarly deranged. The "butler" was one of the contortionists, acrobats, midgets, or other show-business people whom Joe had picked up his years in Vaudeville. Poor Mrs. Cook lived bravely in this cuckooland and struggled apologetically to bring some degree of common sense into the madhouse." The Cookhouse still survives at Lake Hopatcong but is not open to the public.

Cook was diagnosed with Parkinson's disease in 1941. This forced his retirement from show business. He sold the lake house the same year and moved to a more modest residence in New York State, where he resided until his death in 1959.

The Rev. Paul Needle, the curate at the parish church, who organised the search, said: "When you realise that most people are prepared to half-believe in the Pudsey treacle mines, it gives a ray of hope that the much more reliable facts about Jesus may be considered and proved true.

Natural treacle is formed over millenia in much the same way as petroleum. The whole area where Pudsey now stands was once a 'savannah' of sugar beet. Grazing dinosaurs cropped off the exposed greenery of the plants leaving the sugar rich beets lying untouched below the ground. Centuries upon centuries of this occurence led to the ground becoming saturated with monosaccharides as the decaying beets released their simple natural sugars. These filtered down through the ground until they encountered a barrier of impervious rock, where they pooled, and over the centuries under heat from the Earth's core below and pressure from the weight of the ground bearing down from on top were transformed into pure raw treacle, which was then absorbed into layers of porous rock.