Yes-- it's really easy. Make the overhand knot the same way you did before and pull the two threads apart! This forces the knot toward the previous pearl. You'll see, try it! Pattye's Serafil thread and Beader's Secret thread are slippery and slide into place this way.
If you are having too much trouble guiding the loose knot loop toward the pearl, you can use an awl or darning needle or anything thin like that (a chopstick, even) inserted into the loose knot loop to guide it closer to where you want to tighten it. When the loose knot is next to the pearl, withdraw the awl/chopstick/whatever and pull the threads apart firmly. But you don't have to use a tool, not with Pattye's Serafil or with Beaders Secret. Pulling the two threads apart will make the knot slide into place regardless.
