Consumer Reports doesn't recommend commercial drain cleaners because they're too hazardous and not very effective. Instead use a plunger, snake or hose-end bladder. Better yet, prevent clogs by pouring boiling water down a slow drain, or try a product like Drano Buildup Remover or Liquid Plumr Buildup Remover that uses enzymes to break down grease and soap. Most commercial oven cleaners contain lye and are corrosive to skin and eyes. The best strategy is to avoid drips by placing aluminum foil or a metal tray underneath.
Spills are easier to clean up if attacked before they have baked on for a long time.
Many bathroom cleaners are also disinfectants that kill germs, viruses, or mildew. Disinfectants, which are considered pesticides, kill germs on surfaces temporarily, but cannot kill germs in the air or provide long-lasting disinfection. You probably don't need a special cleaner for the bathroom. A good general purpose cleaner and a scouring powder should be adequate in most homes. If you have special medical problems in the home, consult your physician.