Clean My Mac is made by the same folks that also do SetApp (which is one of the ways you can buy/use RapidWeaver) and and number of other great Mac utilities. I think it’s the best of the bunch.
But, in general, I recommend… nothing.
I create Stacks (and lots of other software) and have used RW all day long every single day since 2005. And I also only have a 500GB hard drive (it is a very very very fast hard drive though. 
And I have a number of backup drives and large Dropbox too)
- My recommendations (these are aimed at a novice – but not bad things even for pros)
- Learn to keep track of your new files.
That includes files that you create and the files you download. - Save files to a predictable place.
Always save to Dropbox your folder or your Documents folder. Whichever you like, just pick one. Then check on the size of that folder occasionally. When it gets too big sort it by size and see what’s eating up your space. Delete it if you need to, or better yet, move it to an external drive.
There is a nice tool visually shows you what’s taking up space: https://daisydiskapp.com It’s a pretty great and looks cool too.
Notice these solutions rely on you, a human, to do the job of choosing what to get rid of. I think that’s an important component. I personally don’t ever let any tools delete data. Both because I don’t trust robots to do that and there’s almost no reason to delete data.
External hard drives are ridiculously cheap. (here’s a 14TB hard drive for under $700 - That’s ~ 30 full copies of your entire drive. 
https://www.amazon.com/Seagate-BarraCuda-3-5-Inch-Internal-ST14000DM001/dp/B07H7C4DXR) If you’re going to do anything automated – move (instead of re-move) the data off your small drive to an external, or to Dropbox, or…. whatever.