"He was there. I wasn't about to let him go," he said, but then nodded, even though he had no intention of getting Dylan involved. Snape had made it clear that this would probably lead to his death. He was not dragging Dylan with him. Or Sirius.
"I don't like these things," he said. "If the other person is busy, then they have to leave whatever they are doing or worrying you. They don't work as well unless you're dying, and since I'm not dying, I'm not using it."
However there was something else he could, something he should have thought of before. He summoned his Patronus, the one thing he could do without even saying the words now, and sent it off with a message for Sirius. That would be much easier than the pendant.