Sodium hydroxide and concentrated ethanol will only solvate so much sodium hydroxide. Infact ethanol can be partially dried by this way. This will be a very limitted system. There is also an equilibirum involved depending on how wet the ethanol is, that creates sodium ethoxide. Though I doubt sodium ethoxide is harmful to say DMT, I don't see it as particularly beneficial. It may be possible, I haven't checked the pKa's so don't quote me that sodium ethoxide could be a strong enough base to deprotonate the indole nitrogen leading to undesirable reactions, maybe.
If this were done and if, the MHRB became lysed, and the solvent was evaporated, then a goop remained. Theoretically a soxhelet extractor could extract from this, but it would likely be pretty impractical. Soxhelets are usually used for alcohol extractions of say plant material and not so much used on goops from alcoholic plant extractions. For example one might run a soxhelet of the plant material with ethanol to obtain a goop, rather then the other way around.
It would be significantly easier, and cheaper, to boil the plant material in water. Boil off the excess water. Add base. Then extract.
Also I would like to remind SWIM, that the Tek 'ethos' is geared towards availability for common people. Soxhelet extractors usually fall out of this category. It's more of a science or extraction help post, not a collaborative research project.