well when you get ashes and embers in your throat, it usually means that the bowl is pretty much kicked or about to be. soooo...best thing to do would be to smoke without a screen, and just learn to realize when the bowl is about to be kicked so you don't get any nasty embers or ashes in your throat....another thing that contributes to knowing when you're bowl is kicked is just to know your piece. the more you smoke out of your piece(s), the more you know them and can tell when they're about to be kicked.

hopefully that helps

happy toking!!!