looking at the example from the master thread:
try to use:
Switch cord1 "Cord-1" <poweroutlet> (Cords, Lights, Power)
{mqtt=">[mosquitto:cmnd/diana/cord1/power:command:*:default],
<[mosquitto:stat/diana/cord1/power:state:default]"}
topic structure:
for outbound commands: cmnd/%prefix%/%topic%/power
for status reports: stat/%prefix%/%topic%/power