This video shows leather being cleaned by a professional leather cleaning service in the United Kingdom, They are steam cleaning leather to get the tough soil out the leather grain. As a professional leather cleaner in Tampa FL I would not recommend this type of leather cleaning. Leather in know for its durablitiy as an upholstery covering, but its still a delicate covering that needs to be cleaned carefully.
Heat applied to leather is a no no unless you are repairing damaged color or leather. Heat stresses the leather and can dry it out. Even though in the video the heat is applied with steam the heat is still elevating the temperature of leather and drying it out. Heat on leather can also make the leather shrink. The best leather cleaning services clean by hand using a cleaner and protectant.
There is a close up shot in the video of a cleaned section of leather next to a non cleaned section. You can see how the leather that has been clean looks chalky and no longer smooth. Aggressive cleaning with heat can age the leather prematurely and make it more brittle.
As a professional leather cleaner I would only recommend using a hand cleaning system where cleaner and protectant are applied separately.