What to do with males

A question from a fellow grower:

I live in south africa and had a few volunteer plants come up (i suspect the gardener self medicate :-). The plants are very happy and are doing well, approx 9 feet tall and very bushy. Problem is that there was a few males amongst them and they’ve all started to flower with a lot of seeds being produced. Very small heads with almost no smell. I’ve removed the male plants but is there anything else i can do to reverse the pollenation process and encourage the females to produce new seedless heads? Our 12/12 daylight is on 21 march.