root ball of a deceased plant

[cube]

Hello Ron! I've 2 ?'s 4 ya! First, is it a no-no to leave the root ball of a deceased plant in my ebb/flow system? I'd take it out, but I've got another healthy plant in the same rockwool cube. I'm using cubes in grow-rocks. Also, do male cannibis plants grow clusters of pollen sacs, or just two 'balls'? I thank ya kindly!