I have a minibrew 15 gallon conical and the only times I had the 1" dump clog is when making my DFH 120 clone or other beers that take a huge amount of yeast and need extra time on the cake to ferment. And when it does clog I just sanitize a whisk and use shove the handle up the valve to clear it. If your fast this works but if your slow bad things can happen!
But this can be avoided in most cases by simply opening the valve for a split second towards the end of fermentation. Usually once the krausen starts to drop I will dump just a few ounces out the bottom and do the same about 2 days later. It helps get the trub junk off the bottom which seems to compact more than just the yeast cake. I simply spray the dump with sanitizer before and after and havenít had any issues doing this myself.