I know what you mean, I had visions of taking an axe/chainsaw type implement to it . I tried your suggestion but no luck. After much googling, I decided I needed a pair of circlip pliers to help with this (didn't know what they were but had an idea of the kind of tool I was looking for and google helped with the rest). As pleased as I was with my find and although they did show some promise with their inverted ends, the pair I purchased unfortunately turned out a bit too small to lever through. Following that attempt, I stuck a shoelace through the clamp holes at one point to pull them together and got the hooks to less than a cm away but no joy with the final part of that cunning plan. Finally, my wife had an idea and we stuck a cable tie through the clamp holes (loops) and got the clamp to almost close within a few mm but not quite. The resultant "seal" seemed tight enough and I know it's a fudge but we've just run a wash cycle and at the moment it looks ok. Fingers crossed and if it does go pear shaped, its going to be "bye bye indesit".
Thanks again all your help and sympathy
Ps:Next time I might try doing a few weeks at the gym before attempting something like this