The new Aqua Clean system from Juwel is basically a posh name for a gravel vacuum. But it has been well thought of as two get two clips included which attach to the hose and then one will clip onto you aquarium and the other one will attach to the bucket stopping all the water pouring on to the floor.
It also includes a thumb style shut off valve so that you can go and empty the bucket and then come back turn the thumb screw and the syphon action will carry on. There's a handy little attachment which allows you to clean the bottom of your internal Juwel filter as these can get pretty mucky.
Although £20 does seem a lot you can easily pay £10 for some hose and some rigid tubing so go the whole hog and get the Aqua Clean system from Juwel.