Dealing in cash, as Edwards always preferred, avoids many of the problems of the paper trail, but, let's face it, if a bribe's worth having it's going to be a pretty bulky wad. Finding places to stash the loot therefore requires some ingenuity.
The one place you absolutely do not hide cash is in your freezer. Crooks, and even law-abiding citizens distrustful of banks, have been stuffing bills under frozen foodstuffs since the Great Depression. FBI agents always look in freezers. Dr. Gill could have told Jefferson that.