[Unrepentant VN Vet]

Any holding tanks for something like that would be in blueprints.

Not to mention the piping, valves, control circuits and the switches/computer links to make the whole thing work.

All of which add complexity plus the all-time most hated thing on earth to aircraft design types ---- WEIGHT.

Show this ol' Aero Barrio (if only Flight Testing) guy a C_A owned/operated aircraft dedicated to this sort of thing and I'll cheerfully renounce my Chemtrail Denier status.

Otherwise, those things in the sky behind the high fliers are condensation aka contrails which are benign, unless you're on a bombing mission and those things rat you out to the antiaircraft blokes.

Or you're smoking something really strange before you post about them. /jk

[little jeremiah]

And if you find evidence, let me know and I’ll admit I am wrong, too.