While invention helps to monitor when toilets are due for cleaning, it is education and civic-mindedness which keep toilets clean ("New gadget sniffs out when toilets need cleaning"; May 24).

The Keep Public Toilets Clean campaign was launched by the then Ministry of Environment in 1983.

After more than 20 years, the cleanliness of some of our toilets leaves much to be desired, especially those in coffee shops, markets and hawker centres. Of course, the cleanliness of toilets at hotels and shopping malls is much better.

Among the usual gripes are wet floors, strewn tissue and toilet paper, and people not flushing after use.

There is also one more bad habit among some users. When they rinse their mouths after meals, the whole sink is splattered with food particles. Is it asking too much if people washed them down so that the sink will be less dirty for the next user? Sometimes, one can even find vomit in the sink.

In the quest to conserve water, some building owners install no-flush, waterless urinals. They are not totally odourless and can sometimes raise a stink to the user.

At the end of the day, if everyone plays his part, the cleaners' job will be made so much easier.

Andrew Seow Chwee Guan