I've used reverb on an entire track as a send effect. Wetness is determined by ear for whatever I'm working on, but I think it was about 25% wet.... More importantly was the EQ I had after the reverb. I cut anything that stood out (mostly lows, low mids, and highs). It was very subtle, but still noticeable. Also, the main purpose for using the global reverb was to make everything sound more cohesive. Not sure why you'd want to add a delay to an entire track though...... but if it sounds good....