greasy specimens

[GGANWEILER]

I think it goes something like - first you get the excreting done - then you
 flushes.  i.e.  Disolving the grease or liquifying it IN the specimen may
 promote it wicking along the scaled wings.  And leaves it there when the
 solvent evaporates.  If you submerge the specimen in the solvent, it washes
 the grease off (dilutes it to very low percentage) with insignificant
 quantities remaining once the solvent has evaporated and so a "clean" or
 degreased specimen.

Incidentally,  I use white gas (camp stove fuel)  with reasonably good results.
  This sometimes results in some matting of the fringes, but with a bit of
 gentle brushing much of this can be freed, should it bother you.

A n aside:  I have been using pheromone funnel traps for sesid moth, filling
 the body of the trap about half way with 99% isoproply alcohol.  This kills
 the specimens and when they are removed and the alcohol evaporates it  leaves
 excellent specimens.  The one drawback is if they are in the alcohol for too
 long they do become quite dehydrated and brittle.

And use caution when handling ANY of these solvents - they are volatile,
 flammable and not good in your body.

Have fun.

Gary