Hey,
I'm new around here too but from what I've gathered since hanging around the nexus for several weeks, lye is highly soluble in water and not at all soluble in naptha (or hopefully any other solvent of your choice). The best way to be absolulely sure that there is no residual lye is to perform a final sodium carbonate wash, and even a further step of drying over Epsom salts.
Please fill me in on my missteps with what I have quoted here!
There are also food-safe extraction teks that don't use any chemicals which are overtly caustic or toxic to the human body. I think the most extreme chemical you will find in those is sodium carbonate. Otherwise vegetable oil is used for solvent, vinegar for acidifying, and lime for base. Check out the links in Nexus member Q21Q21 signature for these alternative extraction teks!
Be safe and have fun!
"I now see well: we cannot satisfy
our mind unless it is enlightened by
the truth beyond whose boundary no truth lies."
- Dante, the Divine comedy, Paradiso, as translated by Allen Mandelbaum