Selleys Oven cleaner, is a good oven cleaner, it does have it's drawbacks.
1) It does have quite a strong smell, you must open your doors and windows.
2) if it does contact the skin it will burn.
Wear long gloves.

If you can see past these 2, then this is the best Oven Cleaner from the supermarket.

This is my go to oven cleaner. My best advice is to leave it on overnight. Then it's pretty much just a wipe clean, I don't have to scrub my oven at all.
It is very caustic though, don't breathe it in! Use gloves too as it's awful if it touches your skin.
Other products are less harsh, but just don't do the job that this does.

Product was working ok but it's smell was so overpowering was making us feel sick within 10 minutes and house was well ventilated. Very hard to get smell out of oven as well even after rinsing multiple times. Would not recommend this product

It's good for a handful of sprays and then it doesn't work. I ended up googling it and encountered reviews that said the same thing. Do not waste your time and money on this! It will only end up in anger and frustration trying to get it to spray! Even those handful of sprays I managed to get out of it was weak. Not much came out! Once again, do not waste your money on this awful product!

Works fantastic on removing burn on grim but it is so harsh to breath in. It is truly terrible.
I want use again. You need a full respiratory mask. No good for asthmatic

This is a great product!
Thought nothing could clean my oven & wasn't expecting the excellent result I got.
I almost used a full can on oven but it was well over due for a clean!
I highly recommend this product.

This product works exceptionally well. Made my oven and racking look like new. Does have quite an odor, but its worth it. You can clean your oven 2-4 times with one can.

I would never, ever, ever go back to any other product. It works really well and is fast working. Does an amazing clean and subsequent cleans are heaps easier and faster. It leaves all other oven cleaners for dead. Be prepared for less hours of scrubbing! A fantastic product that I will use forever.
No hard scrubbing needed, just spray and leave overnight. What use to be an hour long job now takes only 15minutes
It does contain Caustic Soda so very powerful for the nostrils! Cover your face well and spray fast!