Toilet brushes make toilet cleaning easier, but they aren't an absolute necessity. If you don't have one, though, you'll have to be prepared to occasionally reach into the bowl with a scouring sponge and rubber gloves. If you prefer a more hands-off approach, maintain the toilet with a drop-in cleaner that disinfects while it controls minerals. You don't have to use a commercial product; you can make one yourself that's just as effective.
Commercial Drop-in Cleaners
The best way to clean your toilet is to prevent it from getting dirty in the first place, and drop-in toilet cleaners can be an effective way to do this. When you leave one of these in the tank, the cleansing ingredients wash through the entire system every time you flush. Some commercial products contain bleach, which is a good disinfectant but can harm the rubber seals in the tank. It's safer to use products that don't contain it, and these typically contain a surfactant -- or soap -- a disinfectant and a chelator, to keep minerals dissolved in the water and prevent them from settling.
A DIY Tank and Bowl Cleaner
You can make your own tank and bowl cleaner that has all the cleaning power of a commercial one by using household ingredients. Mix a cup of white vinegar, 1/4 cup of baking soda and an ounce of dish soap in a gallon of water and pour it into the tank immediately after you flush. Vinegar disinfectants while baking soda deodorizes, and because vinegar is acidic, it helps control mineral deposits. Dish soap safely emulsifies and loosens dirt particles that have collected in the tank and on the inside of the bowl. The concoction will froth in the tank and bowl, so you will know that it's working.
A Cleaning Regimen
Commercial drop-in products are designed to release their cleaning ingredients slowly, but since your homemade cleaner doesn't do that, you have to use it differently. After pouring it in the tank and allowing the tank to refill, hold the flapper up for a second to allow some water to drain out of the tank into the bowl; then wait 5 minutes and repeat. This procedure cleans the entire flush mechanism, including the water inlet holes, where lime deposits often collect. Repeat this procedure once a week to keep the bowl water free of bacteria and the porcelain free of mineral deposits.
Tackling Existing Stains
Vinegar can also dissolve the mineral stains that discolor the inside of a toilet bowl, but it needs time to work. To clean these stains, make a paste with vinegar and borax, and spread it liberally on the stains; leave it for several hours. Spray it occasionally with vinegar to keep it moist. When you're ready to scrub it off, put on a pair of rubber gloves and use a kitchen sponge with a scouring pad. Finish up by wiping the inside of the bowl, the rim and the seat with your favorite bleach-based toilet bowl cleaner and disinfectant and rinsing with plain water.