Oh well the description of that one bottle is spanish, so I thought you could easily order throughout europe.
Ok then it's not that easy - but yes: You can reuse your Naphtha if you freeze precipitate it and then use it again. With the instructions of *Backwashing* with a solution of Sodium Carbonate or something similar you could even use your Naphtha forever.
But just keep this in mind:
Regular Naphtha will still hold ~ 130 mg of Spice at - 20 °C in the Freezer.
This means if you dont reduce your Naphtha, then for like 300 ml you will "loose" ~ 400 mg of Spice that will not drop out of solution. Normally one would simply reduce the volume of 300 ml to get it down to not loose that much.
BUT now if do it, you will need to buy much more new Naphtha. So I would advice do it like this:
Do not ever reduce your Naphtha (with reduce, I mean evaporate a big part of it), but just place it in the freezer directly.
THEN you will still have some hundrets of mg possibly in solution. But if you reuse this Naphtha, then you will stick it again into the next batch. And then upon freeze precipitating, the Naphtha is *already saturated* from the last extraction at - 20 °C.
This means this time and ALL NEXT TIMES you will not loose anything. Now one may say: Ok but when I use Naphtha again, that has already a few hundert mg's of Spice in it, doesn't this then reduce the maximum capacity of Spice which my Naphtha can hold, for the next extraction?
This is not the case, as hot Naphtha can hold dozens of grams per L, therefore even if there is a little Spice left in your Naphtha and you throw it on a completely new batch, it will not hinder your new extraction in any detectable amount!
So basically 5 bottles of that 130 ml Naphtha may be enough until forever.