I've moved this thread to the ccleaner for mac, so you don't get a bunch of windows answers.
Sadly we have few Mac users in the forum, however the first thing i'd check is that you've fully exited chrome and that chrome sync and cloud print are turned off if they are options on Mac (which i'm pretty sure they are).
Same issue here on a MacBook Air 2018 with CCleaner Pro 1.15.07. Hangs for approx 15 minutes at the same point (72% Google Chrome Internet Cache). I've double checked the previously suggested possible solutions, but to no avail. ?
Ironically I can't submit accompanying screenshots in this reply as the form simply states "Loading..." in the attachment section, regardless of browser. <span class="ipsEmoji">?</span>
CCleaner for Mac Version 1.15 is from mid-2018 and only supports up to High Sierra (macOS 10.13). If you are using MacOS 1.14 then the first thing to try would be updating yourself to CCleaner for Mac 1.17.