If you count a wrestling tourney as "in the field". My son got smacked and had a real good bleed going on.... we used a similar product to that one to swipe around the inside of his nose and it stopped the bleed real quick.
In regards to tourniquets... I was always taught that after it's applied, if it's going to be there for awhile, that you're supposed to loosen it every 15 minutes to help with blood flow so that while it's helping to stop the major bleeding, complete circulation isn't cut off from the limb.
