add- ons to optimize cached web storage

[mr666]

I have just updated at 15.1.1:
I have Places cleaner for database and sqlite files, as guessed by Dark Moon.
I can look these process from about:memory;
Firstly:
I would like to know which is it the data specs about cache, because I am sure that it is involved in lack of memory sometimes..
Furthermore: is there somewhere an app to defrag/optimize cache from palemoon directly, in the condition that using ultradefrag with user account is not possible: at the moment I use to manage it with contig command line.
Thanks in advance,
Paolo