Thanks all. I'll source some raddle powder.
I did check though, and it was Tim Tyne's book (my 'bible') that mentions making your own with "children's powder paints with margarine". I think, as a small smallholder, it gets into your mindset that everything is sold in great big packages and, therefore, wasteful!
Tup will go in today anyhow. He's untried, so I was planning to raddle just to check that he's working - it's not critical to be able to work out timings. I'll have an enjoyable hour or two watching them anyway ....