"No," she said. "He poops on the tiled floor in the balcony or kitchen. I just remove the poop, washed the floor with vinegar:acid spray. It was a good idea to use a spray bottle.

I know of many owners whose dogs just use the grate for peeing. The reason may be that the grate is too small or not cleaned after the puppy has had peed. The lady owner whose left finger had a splint and plaster while trying to save her dog from being killed by a big dog at the park, probably did not wipe the grate after the dog had peed, at the beginning of training. The dog is now over 1.5 years old. 

Once the dog is used to pooping onto the tiled floor, it is difficult to re-train him.

"Why don't you put newspapers onto the two frequented floor spots where the dog poops so that you can just throw away the soiled newspaper with the poop?"

The lady said: "The dog used to shred newspapers when he is alone. So I do not use newspapers.

"The dog has grown up and may not shred newspapers," I proposed she does paper-training.        
In any case, the young couple is very happy with the dog. He does not urine-mark inside the apartment despite being a male dog.

SUGGESTION
STAGE 2
But there is some area for reducing her cleaning workload if the adult dog can be paper-trained to pee and poo since she is no longer working.

For example, put newspapers on the pee pan. Let the dog use the pee pan to pee and poop. Use a larger pee pan.

Shredding newspapers may or may not be the adult dog's habit now. Who knows until we try. If the dog can be paper-trained, so much washing and mopping is avoided! But many dog owners have not thought of this 2nd stage as they are quite happy with the status quo. 

"Vinegar:water at 1:4 spray bottle is a good idea. It is meant to neutralise the urine smell in the pee pan or floor," I explained to the happy couple who loved this little rascal whose jugular vein was attacked by a big dog during exercise in a park.  The grate was washed or wiped by laundry detergent. It seemed to work too as the dog continues peeing onto it.  

The tools used is a floor grate + pee pan to toilet train the Singapore puppy. For some owners of small breeds like the Chihuahua, the adult dog will pee and poop on the grate, saving a lot of cleaning. Newspapers as toilet location - problem is dirty paws from newspaper ink. Some owners don't like that.

Stage 2. Few owners proceed to Stage 2. In this stage 2, put newspapers on the pooping floor areas and train the dog to poop on newspapers, saving time. The adult dog may or may not retain his puppy habit of shredding newspapers

For most puppies bought in Singapore, what they want is a clean sleeping area as well as a clean toilet area. Some owners are aware of this.  Sleeping with owners is one of the pleasures of owning a puppy although some dog writers discourage this thinking that the dog will dominate the owners.