Without unplugging the unit, remove the lid.
Place a plastic mitt and boot liner (or a clean plastic bag) over your hand, extending it to the elbow. With your plastic-covered hand, reach into the paraffin and remove the grille. Let the grille drip dry over the unit, and then place it on a nonporous surface, such as a countertop or on top of the upside-down lid. Allow the paraffin to remain undisturbed for a few minutes so that any stirred-up particles can resettle on the bottom.
Using several folded-up, clean, lint-free paper towels, slowly wipe along the bottom and then up one end of the bath “collecting” the sediment in the paper towels. Slowly bring paper towels out of the paraffin, being careful not to let sediment drop back in. Allow the paper towels to drain over the bath until the paraffin stops dripping.
Grabbing the plastic liner from the top edge, pull it over your hand, turning the liner inside-out and enclosing the paper towels within the liner. Discard the liner and paper towels.
Repeat this process as necessary. Replace the grille and lid when finished. Add refill cube if necessary.