Dude... I'm telling you from the perspective of someone who has an extremely sensitive palate,
pyrethrins taste terrible. Considering what I've seen the average toker and grower smoke and say "Hmm... not bad". I'm gonna pass on your judgment of how it tastes.
Clean your grow rooms up and start a preventative schedule.
Nothing beats pristinely clean cannabis once you've had it for a while. Most growers would puke on their bud if they jarred it up and sampled it after using only clean meds for a month.
Can't fathom sour if you've never tasted sweet.
Stay Safe! :D