Googler here. Yes, in my team we have a colleague that is spending one day a week trying to solve a particular problem we have with a completely novel approach. He had an idea after we presented what we are up to in one of our Org summit. Furthermore, it is really a streamlined process, ie you only need your manager approval.

That's not 20% time. That's a project for your primary work area.

When I was at Google (long ago), you were very welcome to do a 20% project. But it was not considered in your performance review.

So you'd better do it outside of your regular job, adding up to a 120% workload.

It is at 3M