Abstract: A toilet that applies pressured air between an upper trap (30) that connects to the toilet bowl and a lower trap (32) that connects to a drain (16), includes a pressured air source (42) that holds a large volume of pressured air equal to at least 30% of the volume of the trapway passage (34) that connects the traps. The pressured air source includes a container (70) with its top coupled though a conduit (90) to the trapway passage, and with air in the container top compressed by water rising in the container after each flushing. The container top lies at least as high as the full water level (52) in the toilet tank when the toilet tank is full.