Prohibit copy/paste for a web application: possibilities?

Our company will present a web frontend to a handful of customers that are at a remote location.

We want to avoid that they can copy/paste our assets (javascript, layouts etc.).

What is the easiest way to do this?

We thought to rent a citrix account where the customers get credentials to log on. Only from this machine they can open a browser to connect to the web application.

We would expect that we can control copy/paste in this environment but are unsure.

Questions:

Can we prohibit copy/paste in a rented citrix machine easily?

Are there any easy alternatives to prohibit copy/paste?