I can't remember where the many discussions are. Could have been on another site.
Let me tell you what I found when I used one.
Mine is a little tiny canister vac looking steamer called The Mouse. I can do floors or cages or anything else with it.
My birds are in a 13 x 13 feet room. By the time I had cleaned one single cage out of 7 the humidity level in the room was over 85 % and the temp was above 90 degrees and it made me so sick I could hardly breathe. I had to leave and let it cool down before continuing. Not everyone reacts like me and not every room is closed enough to cause that kind of humidity buildup.
Then the cages dried there was a white dust, kind of sticky, on every cage. I had to wipe every one of them down with damp cloths. I used distilled water so it was not lime deposit.
The steam itself sterilizes because it is so hot it will burn you and your birds. The birds have to be taken from the cages before cleaning and placed where the steam can't reach them.
There is a small handheld one called Scunci, advertised on As Seen on TV. I think some here use it. Mine is called The Mouse.
Type in small steam cleaning machine in your browser and look at the ones that show. Several different styles at different pricing. There are many brands and styles now.
As Seen On TV has a website, too, so you can look at the Scunci there.
Hope you get a good one.
Annie