My cleaner will seriously eat ANYTHING i put near his face. He is always hungry. My cleaner has a sort of personality, and he's kind of outgoing. He likes to go on my hand when i put my hand in the tank, and even when my hand is on the other side of the tank, he'll scuttle over to my hand to see if there is any food.
So try to put some sort of frozen or dry food, doesnt matter, in between your fingers and put it near the cleaner. It will not be able to resist, and it will scuttle over to your hand and start picking everywhere trying to find food. Dont worry if it bites, it doesnt hurt that much, just a little poke. This hand tecnique will make your shrimp less shy, i think...try it, and let me know how it turns out