We had to strip a load of woodchip from my m-in-laws bungalow. We bought a rotary stripping tool from B&Q I think it was made by stanley . This scores the woodchip without damaging the plaster beneath. Then lots and lots of soaking I put a drop of washing up liquid in to help it soak in. Patience is the key...let it soak for a whole day keeping it damp if you can . Good luck its a horrible job but worth it.
Also I have to do another house so I have ordered a kit from www.wallwik.co.uk the testimonials look good. The two room kit cost �35 but I am short of time so I hope it's worth it. I will report back. PS the rotary stripping tool was not expensive and it doesn't damage the plaster beneath which a knife can do if you get heavy handed and impatient!!
Just incase anyone comes across this, I've found that it's really easy just to do it by hand. :)
I use a scrapper to (carefully!) remove the chip wallpaper. This leaves a lot of it on the wall though - but it's easy to get off by sponging it with water with a bit of fairy liquid in it, leaving it for a minute and then simply scrapping the damp paper off.