I generally don't feel the need to wash my spice, but my understanding is that you can either add water (or a mildy basic aqueous solution) to the solvent, agitate and separate to wash, or you can get the product from the spice, and then wash with the same in a coffee filter. Both should work fine. You want to perform several smaller washes rather than a single big one. Imagine washing a paintbrush- it will be much cleaner if you wash it in 20ml of solvent and repeat twice rather than washing it in 60ml of solvent once.