During our team's attempt at similar virtual training, the pillow method felt disconnected from actual masonry work. The absence of proper weight and resistance means you're not building the necessary physical endurance or technique. It's an innovative idea, but I worry it could develop bad habits rather than foundational skills.
Muscle memory from virtual training? Good luck with that. You'll end up with pillow hands, not mason skills. Better to get your hands dirty with real bricks.