Here's the excerpt from a book by Ian Smith:
By the time we got to Faisalabad for the third test, we were really on a hiding to nothing.
The Pakistanis were simply too good for us, especially as our team lacked John Wright, Bracewell, Jeff Crowe, Richard Hadlee, Andrew Jones and martin Snedden, who'd all either retired just before or made themselves unavailable.
The Pakistani pace bowlers, especially Wasim Akram and Waqar Younis were getting amazing reverse swing. Our quickies, Danny Morrison, Willie Watson and Chris Pringle, were getting virtually no movement after the first few overs.
During the test at Lahore, we got lucky by receiving a big clue as to how Pakistan's bowlers might have been getting some help. Towards the end of the test, Pakistan took the new ball. The umpires gave the Pakistanis the new ball and, as is usually the case, rolled the old one off the park. The local officials were a little slow to pick up on the fact that the old ball was sitting on the boundary edge and for once we beat them to the punch, grabbed the ball and smuggled it into our dressing room for inspection.
There was little doubt it was uniquely damaged on only one side. It had been scratched by something - long scratches too. We took a couple of quick photos before the local officials tried to thwart our plan by retrieving the ball. But we'd had time to formulate some methods of our own.
So prior to the next test, in Faisalabad, Martin Crowe and a few of the bowlers began experimenting in the nets, scratching one side witha bottle top. Chris Pringle, in particular, started getting a vast amount of swing. Even us mere part-timers were able to swing it. Chris decided to have some fun in the next test, and he certainly did.
He put a piece of bottle top in his pocket and used it to scratch the ball, at drinks and at the fall of each wicket. The ball began to swing for him and he found he was also getting much more movement off the wicket. None of our bowlers could get reverse swing - they weren't quite quick enough for that. But Pringle got so much assistance from the roughed-up ball that it didn't matter. He took 7/52 in the first innings and 4/100 in the second. I'll go as far as to say Pringle bowled as well in that first innings as he had ever bowled - it was Hadlee-like.