Drano rots some products, but also jellifies others. It is not a good drain cleaner. To find better products go your Plumbing wholesaler.
you unclog it
Water Jetting
They share the same drain and it is becoming clogged. Drain cleaner in both drains should help.
The under rim jets are likely clogged. You might unclog them with a wire coathanger.
Partially clogged drain line.
What is the classification of household cemicals that are used to unclog drains?
A base, perhaps sodium hydroxide. When in solution this base ionizes into charged atoms that are attracted to the material clogging the drain and also disrupting it's atom structure so that it degrades enough to unclog the drain.
Two common household items that can be used to unclog a clogged drain are vinegar and baking soda. These items can be purchased inexpensively if they are not already in the home.
You should pour hot water down your drain. Hot water will open up your drain quickly. If you don't have hot water put some on the stove and unclog away, and this should work.
you unclog it
No, if it is clogged it must be replaced.
uhhh you unclog it!
If the drains are truly clogged, there will be no breeding in them as no one will be able to fit in. If there are gaps and you find people breeding there, clog the drains even more.
A plumber.
Water Jetting
There are thousands of sites where you can find information about clogged drains. They give great solutions for your problem.http://masterplumber.net/drain_problems.htm
Clogged drains are caused by the accumulation of sticky material in the water pipes. Many times stuff like hair, food, plastic pouches.. gets stuck in the pipes and starts accumulating. Because of this the water from the kitchen or shower sink takes time to drain. Many times the drain pipes emit foul odor. Once the pipes are blocked, either the water stops draining from the sink or the debris starts coming out of the sink and toilets. The clogged water may also start leaking and also rust the pipes.[Source:A-General Plumbing and Sewer Service]