Ah, good old white spirit...
This is a garbage solvent. SWIM tells me that it does pull spice though, but freeze-precipitation is something that works very poorly. And evaporation takes for ages. And smells your house awfully. One can definitely back-salt the freebases in acidic water and evaporate water to get the actives.
But if one is ready to go this route, then he may as well go for a solvent like xylene or limonene that pull more and pull better. Definitely forget the white spirit. Same goes for the turpentine substitute, (which is slightly different from white spirit in that it contains much bigger aliphatics than white spirit).
The best alternative to naphtha in the UK in terms of quick evaporation rates and freeze-precipitation ability is zippo fuels. At least in the UK (and in contrast to some countries like the states and canada) Ronsonol has been found to evaporate cleanly. Better though try some evaporation yourself if in doubt - the composition of these products often changes. The only drawback of Ronsonol and other zippo fuels are their price - to damn expensive.
Another solvent that SWIM has used is Bartoline Low Odour White Spirit. I think he got it from B&Q. This one evaporates very slowly but it worked perfectly for freeze-precipitation.
Hope this helps,
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