Cleaning the faucet in your house
To clean the faucet in your house, take two old toothbrushes, tie them together with a rubber band. Dip the toothbrushes in water, then open the toothbrushes and brush the faucet. The gap between the faucet is often difficult to clean, but tying two toothbrushes together will make it easier for you to do this.

Cracking hard-shelled nuts
Splitting hard-shelled nuts by hand can be painful and tiring. To overcome this, you can make use of old toothbrushes. First, you cut the bristles short, then tie two toothbrushes facing each other with a rubber band and clamp a piece of folded paper in between. Now you have a tool to crack open hard-shelled nuts like pistachios, peanuts, or sunflower seeds.

Cleaning a bicycle chain
Bicycle chains often have a mixture of engine oil and sand stuck to them, which not only increases the weight but also reduces the life of the chain. To clean them, tie two old toothbrushes together with tape so that the bristles of the brushes face each other. Then, place the bicycle chain between the two brushes and rotate the pedals. Now you can clean the chain easily.

Cleaning the keyboard
Computer keyboards are prone to dust after a period of use. You just need to use an old toothbrush to brush the keyboard, the dust will be easily blown away.

Cleaning a comb
A hairbrush is an everyday item that can easily get dirty due to sweat, dirt, and dandruff. To clean a comb, you can use an old toothbrush, dip it in a little water mixed with detergent, and brush along the teeth of the comb. The stains will be quickly removed.