A Microsoft file hosting and synchronization service.
Rather than directly deleting the cache you should use tools like the delete function you described.
As well as the various disk cleaning techniques described below, I also use a tool called CCleaner. I've used it for years, on all versions of Windows from XP to Win 8. I find it trustworthy.
Here are some links to articles on freeing up HD Space. Maybe one or more of these suggested techniques will help with your problem:
How to Use Windows 10’s Storage Settings to Free Hard Drive Space
Even tips for older OS's can still be applicable to newer OS's
How to Use Disk Cleanup in Vista
http://www.vistax64.com/tutorials/76073-disk-cleanup.html
http://www.jakeludington.com/downloads/20050520\_sweepi.html
https://davescomputertips.com/how-to-regain-hard-drive-space-new-windows-disk-cleanup-features/
Disk cleanup- Windows Update Cleanup For Win7 And Win8 - Win Update folder WINSXS
http://tweakhound.com/2013/10/09/windows-update-cleanup-for-windows-7-and-windows-8/
https://davescomputertips.com/free-up-lots-more-disk-space-with-windows-new-disk-cleanup-plug-in/