Here also, you can find hundreds of software that claim to be the best in business and you need to narrow down your research to the most reliable, effective, & rich-featured software only. Now there can be as many ways as you can think of to clean up Mac disk space, but letting it happen automatically helps better than anything.
Yeah!! Cleaning out the unnecessary things from your system will start freeing up disk space which eventually will make things smooth for other programs on your Mac. For example, in this case where the Mac started working slower than before after the disk space was getting filled up, we need to free up disk space by cleaning out the garbage.
If we are damn sure about the problematic place, finding the solution becomes easier. How to Free Up Disk Space & Make Mac Run Faster