Ovens need to be deep-cleaned every three months, and with Christmas just around the corner, now is the best time to do it.

Cleaning ovens often involves using harsh chemicals which can pollute the air and the home and cause damage to your skin if you come into contact with them.

With this in mind, Laura Harnett, founder of Seep eco tools, has shared how to clean an oven with baked-on grime using natural methods.

Laura suggested using lemons and baking soda to clean ovens, claiming that the lemons would "loosen" the grime and the baking soda would "cut through the stains."

She explained exclusively to Express.co.uk: “It takes a while to fully clean an oven in an eco-friendly way so the best time to start this is in the evening after it has been used and cooled or still slightly warm.

"Start by filling a glass or ceramic bowl with boiling water and the juice of two lemons.

"Leave this to infuse into the grease and grime inside the oven and after an hour it should have loosened it considerably to be able to move onto the next step.

“You will need to create a thick paste that is abrasive, as well as eco friendly and cheap to make. Mix a cup of baking soda and few tablespoons of water, add more baking soda to get the right consistency to spread on.

"It needs to be thick enough so it doesn’t just run immediately off the sides of the oven and so the baking soda can get to work."

Laura suggests leaving the baking soda paste on the oven overnight to soak into the grime and cut through the grease.

According to the expert, baking soda is "abrasive enough to cut through the stains but gentle enough to use on nonstick surfaces so it won’t scratch the inside of the oven."

The baking soda paste can be removed using an eco sponge, scourer or a cloth.

Baking soda and lemons can be bought from most supermarkets or online. Tesco Stockwell & Co. Bicarbonate of soda costs 65p, and lemons cost 69p for four from Morrisons.

Eco sponge scourers cost £9.50 from Seep for a pack of four, which works out at £2.38 per scourer. Sonett Eco Sponges cost £3.95 from BigGreenSmile for two.

Alternatively, homeowners could use white vinegar to clean their ovens. White vinegar is a natural cleaning agent that can be mixed with water in a spray bottle and sprayed directly onto oven stains. Distilled white vinegar can be bought from Sainsbury's for 35p.