Good questions Tom, I was wondering the exact same thing. I've run three loads now where I've sat there and watched the dispenser door open. Two of the three times the tab dropped down, not far enough to fall out, but far enough that it was melted before the fill even stopped. The other time it was stuck up in there but the water spray flushed up into the dispenser and in less than 30 seconds I saw powder drop down and out of the dispenser as the wrapper melted. I think tabs in that dispenser is the way to go since it takes a bit more than residual water to get them to melt.