+1 for buying from Axminster as suggested by Derek.
Got mine on a whim years ago without any great expectations as to performance. Very pleased to discover how well it worked.
Mine is bigger and, possibly, easier to handle than the one in the video. About 150 x 80 x 20 mm now. But its worn down a bit! I don't do much woodwork so it doesn't see much use but when I am playing with the brown stuff I keep it handy and frequently touch it to the belt to clear it before serious embedment occurs. Which seriously reduces wear on the cleaning block. Much of the time it seems to pick the embedment out without actually being worn away itself.
I think Blue Heeler leaves his belt way too long between cleanings so needs pretty heavy use of the cleaning stick with inevitable significant wear.
Mine is slightly different colour too, more yellowy-cream, which may mean different composition.
Ones very like mine in size and appearance can be found from E-Bay and other online sources for £7 or £8 (ish).
Clive