I assume you're referencing the top couple of solutions in the SO thread, below, which suggest adjusting sys.sleep()
From the other answers in that thread, it sounds like relevant information includes your OS, system privileges, and anti-virus software you may have running (e.g. corporate Windows 8 (no admin privileges) with McAfee, and I've tested this in R 3.4.0-3.4.3. described in this solution).
Have you tried any of the other answers/workarounds suggested? It sounds like your answer depends on your privileges and/or ability to turn anti-virus software on/off.