I don't have quantitative data, but when I tried 95% ethanol on rue extracted harmala HCl, it appeared that quite a bit did dissolve.  Naphtha on the other hand seems to not pick up any amount of harmala HCl. 

Once I ground up some rue seeds and did a butane extraction on it, like I used to do with cannabis to make hash oil.  I got a golden yellow oil.  The seed residue was used in a standard Tao of rue extraction, but it still did not filter easily and several cleanup stages were still required before good looking product was obtained.  So it seems like a nice way to get to the seed oils, but not a particularly effective cleanup.