The premise is one is using steam to disinfect at 212F, 100C. The fallacy of that is that the steam may be that hot, but it loses it's heat quickly when the steam comes in contact with the surface being cleaned. Also, the 'steam pocket' around the steam outlet acts like a mop and soaks up the steam turned to water and also any dirt on the surface as well. When you wipe again with the same pocket on the implement, you are smearing the dirt you just removed all over the thing you are cleaning. Steam pocket cleaners are useful only on floors in my opinion and only if you have many 'pockets' to use over the same surface. Either that, or you have to scrub your floor to clean it, then steam it to disinfected it.
I do have a steam cleaner, the canister type with a high output nozzle, that I use on the cages four times a year. I spray the steam on the cage area to wet it, then wait a few minutes to loosen crusty stuff, then close blast the steam on the skirts and bars and catch pans and wipe away the dirt with paper towels which are disposed of promptly. It gets crud out from between gaps easily and around welds as well. However, if your cage has a poor paint job, you will find rust eventually. I have been using mine for 9 years and it is a good alternative to power washing for someone who lives in the north east and not often able to powerwash my cages.