If you're running a workshop or speaking at a conference or providing training to employees and you tell the attendees that they may take a bio-break, they should carry you to the restroom and flush your head in the toilet.
Simply announce the break and the amount of time that you are providing for that break.
There are few more asinine phrases on this planet than bio-break.
Also, to whatever amount of time you think is appropriate for the break, add 10 minutes. Your attendees will return more refreshed and be better prepared to listen.