Oven cleaning!!!

[mummyofteens]

Please pass on your best tips for achieving a lovely clean oven :)

I am really debating about what to do with my oven. There is a Groupon offer today for an oven clean for £35. I have a range cooker though (2 electric ovens, grill and 7 gas rings), so imagine I will have to pay a surcharge. However, I have a packet of Oven Pride in the cupboard, so should I save my money and just use it???