I make nothing of it Rich, because when you rub the ball against your trousers (a time honoured practice which has the imprimtaeur of the powers that run the game) you do it in front of everyone. Likewise, these days if there's mud on the ball, everyone knows after some of the events of earlier this decade and late last, you go to the umpire and say "There's dirt/mud on it, and I want to remove it" whereupon the umpire looks at you and says "Ok".
I can't imagine Tresco or whoever else does the other malarky walking up to an umpire and saying "By the way, I'm about to have a big golly on the ball and I've been using these things in my mouth which I've worked out after a few years of experimentation do funny things to the ball when it's propelled in the general direction of the batsman. Is that ok?"
Having said that, there's nothing wrong with the time honoured tradition in park cricket of taking a ball that's wet when you're forced from the field and placing it in the pie oven for 45 minutes while the ground dries, then using it again. The fact it now has a seam about 3/4 of an inch hgh is merely coincidence.
Try it. It works. It's not cheating. I mean, how can you know it's really had an effect on how the ball behaves, it's mere supposition, etc. etc. But, if we bowl with it in that condition and you happen to edge one, I do expect you to walk. It's only good sportsmanship.