The conclusion I reached was that the only solution would be to create a virtual environment for each client, which would be eliminated when he leaves.
I never came up with an idea. But, to create such a space, I would have to create a system providing security for all clients.
I don't know if operating systems can be set up in a few minutes. Most operating systems take more than 20 minutes to set up and install the necessary software. Most people use browsers only to do their work, so you don't have to install any software. You must have dedicated employees to set up the operating system after each session. You may charge them extra fees for that.
For example, Your client might have two options.
One - Fresh new operating system which is totally safe to use. You may charge high fees for that.
Two - Used operating systems which may have viruses, which could be unsafe (Nobody knows). You charge them a regular fee for that.
The point is; No other cyber cafe offers such variations. So, if someone cares about their privacy, they should choose package number one. If someone chooses package number two, ask them to change their credentials after using the computer to avoid issues. You can print a banner and write them in it so you don't have to explain it every time.
If you like long-term and slow traveling, you might consider carrying your laptop. Or maybe it doesn't give you a proper vacation feel if you work on your laptop 
