Automatically clean browser cache Mac with CCleaner

Hi,

I know the pro version of CCleaner will automatcially clean browser cache but I can't get it right now. With the free version, is there a way to automatically clean the browser cache each time you start the computer. I have a Mac OSX Yosemite and I could use Keyboard Maestro or something similar but I don't have enough experience yet. I use Firefox and Safari (mostly Firefox). Anybody have an easy way to to this?

Thanks,

Greg