all this discussion reminds of a "chorai" technique we applied on cricket balls during our u-13 and U-15 days. Naturally, one side of the ball was kept as shiny as possible, the other as rough as possible - to assist swing. that's rudimentary for any fast bowler. However, what we used to is - when the drinks guys came in, we'd "accidentally" drop some water on our trousers, to the right and left of the groin. Then, looking to "shine the ball" on it, we'd actually press the roughened-up side to the wet trouser, and get the ball's leather to soak it up. Within a couple of overs, one side got substantially heavier than the other - for our bowlers to swing it with little effort
