Something I have always used to augment Ccleaner to clean up temporary files is something called....
Temporary File Cleaner (TFC.exe) from here
http://www.geekstogo.com/forum/files/file/187-tfc-temp-file-cleaner-by-oldtimer/
It seems to always get a few more megs then a default run of Ccleaner, which I always run first before running TFC.
I just ran it on my Wndows 10 install and it adjusted my temp files down from .99GB (999mb) to 249mb.
It's probably important to note that Windows does require some Temporary Files when it runs, so cleaning them completely is probably impossible.
If you choose to run this tool, it may appear (to you) to be hung.
It's not, just give it time to completely finish.
Right click it and choose Run as Administrator.