If you have a very high enough refresh rate display, then yes: just flash alternatingly black-over-white and white-over-black text (i.e. invert it). We perceive essentially a low-pass filtered visual input (with limitations like neural firing rate), eventually it should appear as just uniform gray. Maybe adding some confusing elements might make it feasible at lower refresh rates.

Maybe not exactly what you meant but it reminded me about the following: When one of our apple servers failed a decade ago and just vomitted out walls of error logs too fast to read anything,the apple support guy we called took his smartphone and made some photos to read and fix the error.

You could probably do it with timing tricks related to video refresh. Wait until the monitor has finished refreshing, then draw the text into the framebuffer. Leave the text there a short while, but erase it before the monitor starts refreshing again. Repeat.

The screenshot would have a chance of capturing the text, depending on exactly when the screenshot pulls pixel data out of the framebuffer.

This might not work on certain devices. You need access to the refreshing timing information. The capture mechanism used for screenshots might also vary.