The best way to seperate the layers is with a sep funnel.

The warmer the solvent is, the more power to dissolve it will have.  But don't exceed the BP of the substance, say 140F is safe.  Mix it up vigourusly for a few minutes and allow it to settle out before seperation,  do 2-3 pulls is all you need.

After seperation, just pour the clear liquid off any remaining emulsion/debri, into your evaporation plate.  Add the remnant left in your pouring beaker back to your main vessel that you've left you basified potion in for the following pull.

On what you think is your last pull, pour a tablespoon amount onto a mirror or clean glass plate for quick evaporation.  If it leaves little or no visible residue then you know you've transfered all your going to with that pull and the previous pulls.

Other solvents have more dissolving power than naptha for the wanted substance, such as heptane.

Better to do a freeze precipitation, than an evaporation.

PS:  better to process as much material as you can confidently handle at one time.