G' day Jamie.
I use thinner to smoothen some sections firstly, then I proceed with drybrushing to polish.
Afterwards for total smoothening Talens quick drying painting medium, feels like baking oil.
a part of an ear snapped, needed to largen necksection and bake the head for second time, ears are fragile but was easily repaired in the way I described above.
Fimo and co are very susceptible to thinners, I always use a little bottle which I close everytime when working with it.
thanks,
Rene