I have found 50C to be the point of diminishing returns for naphtha pulls*. Any hotter just creates more risk and makes for dirty pulls. I do this in a water bath (electric heat only) with the lid neither loose or tight but snug to avoid building pressure, and leaving at least an inch empty at the top so that only air and fumes are exhausted, just tighten enough to build maybe 0.1PSI relative/800Torr. And always put a couple layers of dish cloths down under your solution jars, or direct contact between the glass jars and metal/Teflon pan can cause them to break. I have had this happen before and it's a noxious cleanup that can damage cabinet finishes and all flooring surfaces barring tile.
When temperature is reached, I'll tighten the lid (for canning jars; rubber side down; and agitate. Loosen lids and return to water bath for a couple more cycles before removing the naptha. For canning jars, remove the lid, wipe down the rubber/coated side and replace metal side down. You want a good seal for the agitation, but leave the rubber/coated side in contact with solution for a minimum time.
I'll usually hold them at 50C for a minute or two to ensure heat penetration. Using this method, only a slight and brief puff of air and solvent vapor is released when opening the lids. There's nothing too dangerous, but still wear safety gear and loosen at arms length. If using canning jars, you can just install the rubber gasket upwards so that the "seal" is glass to metal. Just make sure you scrub down the top of your lid with the solvent being used so that any ink or varnish doesn't make it's way into the solution. This is a wise practice also in that the combination of NP solvent and 11+ pH can destroy both the rubber seal and the inner coating of the lid, introducing potentially harmful compounds into your spice. With stronger bases like lye, this degradation occurs very rapidly.
A more efficient and safe method to pull faster is to use more pervasive NP solvents likes xylene or DCM, evaporate and then clean up using smaller amounts of naphtha to re-x. Then the safety issue is venting the toxic fumes. In this case there is no need to apply heat except for in small amounts to accelerate evaporation.
Some day, when I have a proper glassware set up, I plan to drip DCM (more dense than water) through the basic solution into a heated triple neck RBF at 40-45C. The DCM fumes will travel up a column and a condenser for a continuous drip through the separatory funnel at 25-30C containing the basic solution. The third neck of the RBF will be for the thermometor and a p-trap air lock (3-4" H2O) will be at the top of the column. Once the pull is complete, the separatory funnel could be replaced with a collection flask and the third neck could be plugged to remove the DCM from the RBF and recycle into the collection flask.
I digress, but yes 50C seems to be the magic number (naphtha and probably heptane/hexane as well) for being both clean and efficient and not significantly more dangerous*. Compared to room temperature (23C), naptha seems to pull 25-35% more at 50C.
*It's kind of beating a dead horse, but never use any kind of flame or ignition source to heat flamable solvents such as any of the above mentioned. It could put many more lives than just your own at risk and possibly getting locked up on top of having your house burn down and the insurance company refusing to cover it. Even when using electric, make certain that there is no flammable material near the burner as this could auto ignite and cause catastrophe. I once had a close call trying to boil down acetone over a natural gas range. Luckily, I had been through some basic fire fighting training about a year and a half earlier and there was a wet rag handy that I could throw over the pan of flaming acetone. Even if using electric, I would highly advise having a couple large drenched towels nearby just in case as well as a large fire extinguisher (read the instructions).
