Ariel Stain Pen Book

I have been looking for Ariel Stain Pen around in the Dutch supermarket, unfortunately they do not sell it here. I hope we will have it soon, because it is just so convenient! I am quite accident prone, so it will be so great if I can simply whip out the pen and clean my shirt. I can imagine how much I will need it if I morosely spilled something when I am with my date or in my way to a job interview. Apart from that, Ariel is creating a good deal of buzz as part of their campaign to introduce the stain remover pen to the public. They placed the pen inside a self-help book 'How to Help Get Rid of Stains on the Go' which is left around cafes and bookshops. When found, readers are encouraged to take it and leave it anywhere, then register as well as review the book in www.bookcrossing.com. However, I wonder how do they refill the pen if they don't know its whereabout?