If so this is a complicated usage of buying shares pre-dividend payout, ie, just before they go ex-div. How it affects the shares in simple terms is none whatsoever. Obviously the price of the div is reflected within the price after the div has been paid and thus makes it price neutral.
If you have been informed there is a cheat here to make a stack of cash, forget it, it doesn't exist. However, one can use it to offset taxes but like I said above this is a complicated matter and should be carefully carried out between you and a professional accountant as every persons accounts are individual. Also if not carried out professionally and accurately could lead to paying more than you would have done initially, you could also potentially cross the line of tax avoidance into tax evasion. In short it is used mainly for tax avoidance which is legal but not as a get rich quick scheme.
Putting it bluntly, if you are making a million and want to pay as little tax as possible there are far better and easier ways to do so. Your personal accountant would advise you on this.