Oven cleaners: dress up if you want it fast
The best oven-cleaner is someone else. But should you be forced to do it, only one tested by the French-Swiss consumer mag Bon à Savoir for its January 2017 got rid of those persistent stains fast.
It's the Wepos Four & Grill, for CHF9.95 at Hornbach. It did best in the "two-hour" test. But be warned. It contains caustic soda, which can burn the skin. You'll need gloves and protective goggles. And don't clean the oven in your underpants, as the BàS photo has it.
The others tested need you to leave the oven overnight. Best of these was the Migros Potz Ofen-Four (CHF3.95), followed by Coop's Qualité et Prix Flup Power Mousse (also CHF3.95). But there was only one-tenth of a point between them, and none rated "very good".