I deal with crypto and other financials. My pc runs Zorin16 (Ubuntu). I use Bleachbit and Sweeper intending to remove contents of swapfiles, caches, temprary files and all the sneaky places my confidential data might lurk.
As far as I can tell, neither software deals with swapfiles or all caches or all temporary files. As I don't know linux that well, I find it hard to locate these files to check or to include them in custom settings in bleachbit.
Any advice please? Any other software (that can be automatically installed on Zorin as I can't manually install or compile etc)?
Swapfile and cache files are constantly destroyed and recreated on reboot, so there is no need to delete it because it will be the next time you shutdown. The point of the swapfile is to store information from physical memory temporarily, on disk, when physical memory is nearing full capacity. Usually it is an item that is idle in the background, an app you just closed, or even portions of the desktop environment... anything not currently in use.
The swapfile is also created in random locations in the drive. There may be several sectors and clusters (an area) of the drive designated to the swapfile, which isn't used for any other purpose. This allows the drive to survive this file and causes overwrites of the last location as it will overlap the previous swapfile's location to an extent. Making it even more difficult to recover information from that area in the drive.
Crypto and financial information changes so often that it would not be a process that is ever sent to a swapfile or cache (if you're following them online).
Cache files are program specific. That means that the system cache will have no idea what's in the browser cache. So any software you use to access that information is the only software you have to focus on. If you're accessing accounts with static figures that only get updated periodically (like a bank account), the cache files may hold a record of that. Your browser should have an option to delete temporary data upon close. This, along with the fact that the cache files are overwritten, again in the same location, constantly... would make it difficult to recover that data unless they accessed it immediately after you had accessed the site. If bleachbit overwrites the browser cache files, you are more than safe.
Most users will never be directly targeted, even with crypto mining and bank access, by hackers because the chances that they will get worthwhile information is slim. Most viruses, Trojans and malware are on the web to target organization Microsoft machines. This is because windows is used the most out of all the OS options and companies have more money or worthwhile information than any individual ever could. Linux hasn't had any remote privilege escalation scripts succeed (they have always been local... requiring the user to already have physical access). Linux makes up only 3% of the OS market (rounding up) and is more secure than any windows machine will ever be. There are very few viruses/malware that target Linux machines because they fail to gain the privileges needed.
I understand your worry, but the fact that you are doing these things in a Linux box and using bleachbit (I'm figuring with the firewall enabled and configured), you have nothing to worry about. You're already doing more than is necessary. Take a deep breath... and relax, you're safe.