Steam Cleaner on Unsealed Floors

Oh no no no NO!
Moisture of any kind on / into the wood is very bad.
Steam cleaning on sealed floors isn't that great either, but people do it.
Cardboard is never the same after it has been wet.
Flooring is not that much different than cardboard.

I've stripped and waxed unsealed floors before.
It's not quite as complicated as it sounds.
If you do a real good job, you might only need to do it once every few years.

When we were kids and the wax had dried and it was time to buff, we"d put on socks and floor skate (it's fairly slippery).

http://www.wikihow.com/Strip-and-Wax-a-Floor

I have a Shark steamer. In the owner's manual it has this warning:

"Your steam mop is designed to clean hard floor surfaces that will withstand high heat. Do not use on unsealed wood or unglazed ceramic floors. On surfaces that have been treated with wax or some no wax floors, the sheen may be removed by the heat and steam action. It is always recommended to test an isolated area of the surface to be cleaned before proceeding."

I hope that helps you.

I have a shark and I use it on my laminate. I just bought a new one because I didn't know you shouldn't use tap water in them. The minerals clogged it all up. Anyway the new one has three steam settings one if specifically for laminates and surfaces that don't like a lot of water.

I use them all the time, if you have any other surfaces in your home like walls, floors, metal stove doors, etc...then the steamer will work wonders on them when used so if it doesn't like the floor too much you still have a major use for it.

The wood grain will swell and it will ruin your floor. My parents have old hardwood. They sanded and sealed theirs and my uses a damp mop. Damp, not dripping.