Bought some of this stuff from the states, it's great!!! I'd recommend this over any other product, specially wire wool!! Took literally a few minutes to do a whole fretboard and buff it up, bit of lemon oil to top of as well. I think it cost me about a tenner and a pack will do 20 basses/guitars. You can't go wrong!!
Only downside is I probably wouldn't use it on my maple board without taping off the wood, if the frets are particularly manky it just spreads the filth all over, on a nice maple board it MAY not come out. I don't particularly want to be testing it either! If anyone else has any experience using this on a maple board I would be interested to hear it.