O Wow 190 L Sorry yeah Erin is right, that is to small for any Tang, I tought it was 190 gl, But How do you know your cycle is over have you ben testing ??? How long since initial set up ??? and did your amonia, nitrites and nitrates all spike and then go down ????
If you tested and all this has already happen then you should be safe to add 2 Clowns. Make sure you wait atleast a month before adding any more fish.
As far as your cleaning crew goes. Have you ben feeding them ??? Being as there is no fish in there to feed and the tank is not that old you might not have a good food sores for them yet. You might want to add algea waffers or something like that for them to grub on.