Yes Luke it gets tricky in the damp and wet!
We generally find that BB Greens work very well with Silver Cut Staggers on a 2wd and BB green fronts on a 4wd.
If it's pouring with rain the grip can actually come up. I've raced in soaking conditions and been very surprised by how much grip there is at Stotfold.
If only damp BB whites can work too.
I'd recommend a selection of the above for Fast Forward on Wednesdays as when the damp sets in it can get a little slippery.
Hope that helps mate!