Catching cleaner shrimp???

[Stones]

Just wondering if anyone out there has any ideas of how to catch a cleaner shrimp in a fully stocked reef with tons of live rock and corals.

I've tried the pop bottle trap with a funnel made from the top of the bottle on one end. It worked really well to get one of my cleaners out but the second cleaner appears to be wise to the whole situation. Catching with a net is impossible as there is way too many corals and too much live rock for him to hide in. Removing the rock is also not an option. Any other ideas would be greatly appreciated, thanks.