Lets face it; we pour everything down the sink and after a while it starts to smell pretty foul.
You can disinfect your sink pipe and drain by mixing a gallon of hot water with a cup of chlorine bleach and pouring the solution down the drain.
If your sink is made from delicate material such as natural stone you’ll want to carefully pour it down the drain so it does not come into contact with the sink.
You can also keep a sink smelling clean just by pouring several buckets of boiling water down the sink each week. After you use boiling water to cook food such as pasta or making tea, pour the boiling water down the drain and it will kill many germs near the top of the drain and flush them away.
Finally, there are bacterial powders that you mix with water and then pour the solution down the drain. If your house uses a septic system, then this may actually be your best solution, since it will help keep your septic healthy as well!