I just discovered that the DMR allen key pedal pins seem to fit into my cheapy VP-266 pedals that unicycle.uk.com sells, instead of the rubbish pins in there already. It makes it grip like a quite good pedal.
So anyone wanting really grippy pedals but not wanting expensive ones might want to do this to their ones. Get DMR pedal pins from most bike shops for £3 for 16, or 3mm grub screws (2 or so mm allen key needed) from model shops.
Joe