Well, here is a
link for a site created by the University of Nebraska-Lincoln where Black Knight is listed as one of the recommended aerosols for roach control. If it were a product that contained anything illegal, I highly doubt a state-sponsored university would be advocating its use.
Also, there appears to be very little actual evidence (lots of supposition and lectern thumping, but no evidence) that humanity is doing ANYTHING AT ALL to cause detecable depletion of the ozone layer. For this individual to suggest that it is being damaged by people spraying their tanks with Black Knight borders on the absolute ludicrous!
A little bit of punctuation would have helped in my comprehension of what he was trying to say . . .but just barely. Oh, well!