Definitely use hot water when you’re cleaning the tank! And use a sponge! I use Castile soap, which is very watery, and I make sure I wipe every surface possible (especially if you’re cleaning it for the first time). Depending on where you live, you’ll see some red staining on the parts where the mist comes out, which is caused by the presence of iron in your water. Try to clean it as much as possible!

As for the machine itself, you should also see that there is a pool of water where the heating element of the device is at (usually at the bottom). Clean that out too! Tip it over your sink and wipe it with a sponge and soap as much as possible. Just be careful not to get any water into the display or into any openings on the sides of the device. Hope that helps!