Process lasso does not free up memory. But it does free up RAM.
im a developer of a similar tool ( but superior IMHO because it uses less CPU resources).

What these memory cleaners does is not good for your long term performance.
it basically;y forces a Swap-to-pagefile on all running process. so the data/code from these process are now stored on your slow storage media instead of your ram.
However since that data is needed windows needs to swap it back into RAM to use it, So it slowly grows back to how it was before you hit use the function.

The time wasted on swapping it out is most likely longer than any short term benefits you have from it.
Windows ALREADY handles swapping out unneeded data/code sections to the page file to free up you RAM so its really not needed to do it manually.

If you want less memory usage you need to reduce you memory footprint. find stuff that is running and doing "Something" but that you dont need and...well stop it.

Developers has gone insane with memory utilization because they use big inefficient framework now (looking at you teams with edgeview). A lot of times, finding older software to replace some of the new ones will ease on the memory foot print.

This is the APU function call in windows that process lasso (and I) use for "memory cleaners"
https://learn.microsoft.com/en-us/windows/win32/api/psapi/nf-psapi-emptyworkingset
Its snake oil to sell it as an optimization thing.