ok, so I put the gooey jizzy gel stuff on the oven at 830 this morning, the box says it will work from 3 mins to 3 hrs depending upon how dirty it is. I knew mine was rank as did the Jamie Oliver lamb cooked on the actual shelf yesterday, plus haven't cleaned it in about 6 months and then it was only half-arsed. It's still on there now, and I really can't be arsed doing it yet - has anyone left theirs on up to 8 hrs?