Season before last, we had a new member to our fly club that unfortunately, had the personality and arrogance, that no matter WHAT, anyone said, did, caught, tied, cast, you name it, HE "could improve on it, do it better, faster, longer and with better results".
We thought, after a few weeks of this, (on every club outing the club went on and he came along), that simply "accidentally having his belly boat deflate, out in the middle of the lake we were all fishing at the time, might look a bit suspicious. But, without resorting to that tactic, we were saved when one of the club members noticed that "After every fish he caught, he'd reach into his vet, retract a small spray bottle and spray his fly with it, before casting back out again".
That night in camp, while he was off to the showers, (that was ANOTHER very annoying thing about this guy, he BATHED, even though this particular outing was only 6 days long!), we got into his vest, took out the bottle of "Clam/Shrimp Oil Spray" he'd obviously been using and "accidentally" poured it, all, into his thermos of coffee.
Hid rod had been leaned up against a tree, too, still rigged up. So, we cut off his fly and tied the empty spritz bottle of oil to his tippet and allowed it to swing in the breeze. No one said a word, when he returned from the showers.
He was still damp, from the shower, it had grown chilly with the sun going down, so he dove for his coffee, as soon as he returned to the group. Needless to say, "the faces" he made, the projectile vomiting of the "Sea Food Coffee" and the sight of his empty spritz bottle dancing in the breeze, from his rod tip, made the man realize, "He'd possibly crossed a few too many lines, his repeated and constant bragging wasn't much appreciated and we weren't impressed with his "secret fishing methods"! (using any kind of "fish attractant on fly only water is against the law in the state of Oregon. We were fishing a fly only lake).
His change in character and personality, as least around club members, was amazing after that trip. He began "Asking questions", instead of ALWAYS having the perfect answer. We never saw him using any additive to his flies, after that night. This fall, he's running for Vice Pres, of our club and the way he's changed and with the new attitudes he's embraced towards the club and its members, I'm betting he gets elected!