The dome creates a 'mini' greenhouse. Its purpose is to retain humidity & prevent humidity fluctuations. When a clone is cut it continues to transpire at the same rate as when it was attached to the plant, but it now has no roots for water uptake. That cut at the base of its stem takes up much less water than a root system. A drastic drop in humidity can seriously dehydrate a clone, sometimes causing its death. It won't drown unless you over water. See too much condensation? Open the dome/ baggie just a little untill it evaporates. Can you clone without the dome? Sure, as long as you have higher humidity than in the average home. But most of us don't. When you have a LARGE group of plants in a closely contained area, transporation raises humidity. When this isn't your situation, domes/baggies increase your success rate.