As mentioned above - the easiest method, by far, is to pull the standppipe and flush it to the sump. I have had to do that more times than I care to remember. My solution, on the overflow without teeth, was to take a piece of eggcrate the same width as the overflow and ziptie a similarly sized piece of vinyl gutter guard to it. Place the eggcrate inside the overflow and the gutterguard on the outside and it is pretty much invisible.