Sanitizing data on Shiny dashboards for training purposes

I'm trying to sanitize data so that I can train people how to use a Shiny dashboard.

We have a Shiny dashboard that contains personally identifiable information and users authenticate into the site. However, we need to train people to use the site in a group setting. We first attempted to sanitize some data and create a dropdown filter for "demo" so that we could show only the sanitized data during trainings. Unfortunately, this introduces an issue because these sanitized data are included in any All calculations on the dashboard. We were trying to avoid creating 2 dashboards, where one is for training purposes only, but maybe that is the only way?
Does anyone have another suggestion or have any experience with this issue?