Teams of six swimmers will be smearing on the goose fat as they aim to match the feat famously achieved by Little Britain television comedy star David Walliams four years ago.
The 21-mile relay swim from Dover to France is one of five major events being held to celebrate the 20th anniversary of the Kent Air Ambulance.
Teams from Air Ambulance at Dunsfold near Horsham, West Sussex, will also be involved in raising funds towards the £1.7m-a-year cost of keeping the helicopter airborne.
Each team will consist of two supporters and six swimmers who will take it in turns to swim for an hour. Only five boats are available, so anyone interested is urged to reserve their boat now.
East Sussex fundraiser Bridget Pepper said, "This is a first for the charity.
"It's going to be gruelling, but something that participants can be very proud to be part of.
"It's not something you do every day. Indeed, more people have climbed Mount Everest than have swum the channel – that's how challenging it is."