i've not got one so cant comment, but the idea of dry dust with a wet steam cleaner to me looks as if that is asking for trouble with clogging. so thats why i've not got one
shower mould is a tricky one, i have had success on the grout, but depending on the sealant used i have had variable results, the sc 5 with the water droplet setting has better cleaning for things like scale on taps, if steam cleaning mould, wear the appropriate PPE mask as you should when dealing with mould with any other cleaning method.
Out of all the steam cleaner I’ve got it’s the best, there is a link to a white version at a discount price over a yellow version in my links at the moment