I put a bag of ghost shrimp in my tank about 6 months ago. My RTG was about 7in though.
They all went to the bottom, the do a good job of cleaning. never seen my aro hit the glass because of one. It picked them off while on patrol, there are still a few in there because they breed.
You could say the same about most live food, feeders, chrickets etc.
When i put crickets in the tank i put about 15 in at a time. The RTG goes mental eating them, many of them swim to the corners to try and climb out, it just picks them off gently.