Note again too, I didn't say take a shower with your guitar
I said take a shower, then put your guitar in there. You want the steam in the air to come out and not drip all over your guitar. But the bathroom will be nice and humid for several hours afterwards as all the water droplets evaporate on the walls and counter tops and so on. You will probably read all sorts of horror stories about doing it this way but I've tested this method and I know it works safely when done right.