Cleaning Start Up Disk

What do you mean by "cleaning" and why do you think that anything needs to be cleaned? This is not Windows. The hard drive has no "memory" asyou are using the term. It has space. (Like a file cabinet). If you need to free up space then delete files you don't need. Using third party "cleaning" apps is a waste of time and usually will muck up your system.

I think I have a similar concern.

I'm wondering if there's a way to reduce unecessary system stuff that's been building up.

Here's my post on Avid>> Cleaning Up System Drive

There is very rarely any "unnecessary system stuff that's been building up" on a Mac. As someone else has said above, this isn't Windows. The Mac OS is good about cleaning up after itself, and the amount of space you can recover by deleting unused printer drivers, language customizations, etc. is insignificant in relation to today's hard drive capacities: it's on the order of one GB. If you're so short of space that that will make any difference, you need a larger hard drive right away, not a way to clear another few MB on your existing inadequate drive.

I agree with sig and eww, there's no need to "clean" your hard drive. There are many utilities that claim to do that, but the things they do can harm performance or even damage your system, requiring it to be reinstalled. One popular gimmick is "cache cleaning." Although a corrupt cache can cause problems, that's rare (I've never seen it happen on any of my Macs), and caches are important to keeping your machine running fast. Frequently deleting them, which is all a cache cleaner does, is a bad thing.

Don't treat your Mac like a Windows machine, and don't install utilities that are the digital equivalent of snake oil.

Thanks. I updated my Avid post.