Hi Manan,
The Cat chokes much earlier than it should be because of the very poor fuel quality that we have here in the land of the Pure. So, unfortunately, even if your consumption and/or pick have not been drastically effected yet, the cat most probably does need attention.
How can you diagnose if the cat actually does need attention? Have the exhaust pipe opened (in the engine bay...Very easy process, Honda Dealership have the requisite tool for that) and peep in. If you see lots of rust and you cannot see the mesh when you shine a light in, it needs attention.
The problem with Honda doing the cleaning is that they use very corrosive acids which take off a layer (it some precious metal which actually makes the cat effective) of the cat and renders your cat useless. Also times out of 10, they will break the cat. Assuming the process goes well and the cat is not broken in the process, due to corrosive-ness of the acid used, this process can only be carried out once or twice. Thanks to our fuel, the cat needs to be cleaned frequently.
So what Honda does, is definitely not effective!!!!