I think you call it kiln wash in the US, but it's the goop we put on kiln shelves.
I gave my shelves a good seeing to at least ten firings back and everything has been fine with no disasters or wash flaking off or anything nasty happening at all.
However, after my last firing, when I unloaded the kiln, all of the kiln posts were very slightly stuck to the shelf (only on the bottom), it was very slight, just enough to notice but not enough to disturb the lower shelf when plucking them off.
I don't think i'm supposed to put batt wash on the kiln posts, but is this an indication that my shelves need re-doing?
In case it's relevant, all my firings are to ^6 or to bisque temp.