packapoo wrote:I fancy I can see a flaw in that idea. Tho' might be just me....

What's your concern? I'm guessing either.....
Contaminating the wash with heads? The quantity from a spray gun is tiny, maybe a table spoon, to do my 60l fermenter, most evaporates off, and even if it didn't, what's and extra 30ml when you are collecting 1.5l heads from the spirit run of 2 stripped washes.
Or
High proof touching plastic? I'm not soaking it in the stuff, contact is maybe a minute, it really does evaporate dry, then I'm chucking 50l of wash in there. If you're not comfortable doing that, then don't do it. They cart NGS about in HDPE totes, so if you drink commercial gin, that base spirit has been in contact with the same type of plastic for much much longer.