got that drain at work. i would be concerned that any mesh type product will cause leafs to build up and not let water through. like with most gutter products, resulting in the gutter not working at all.
the only good way i know of is getting the water speed about right. to slow doesn't wash the leafs down the drain, to fast the water runs off leaving the leafs behind. at work we have a big hose i can easily wash it out with.

