In Malaysia public toilets tend to vary between absolutely disgusting to merely unpleasant.
If planning ahead has failed you, or you are out for a long time, then you will have to avail yourself of the facilities available.
I live quite centrally, and do not have this problem too much, and thus am no expert, so this will not be a definitive guide, but provides what help I can.
In Penang, the good hotels will obviously have a reasonable standard, and if one is nearby in your time of need, this is an obvious solution.
Unfortunately, the big malls are not necessarily so good.
Tesco, at Tanjung Bungah – the first and second floor toilets are acceptable.
Straits Quays toilets are good, as you would expect.
Island Plaza toilets were OK, and with the refurbishment ongoing there may improve, or have improved. If you are across the road at Prima Tanjung you could cross to Island – but you may have to drive across as it is quite dangerous as a pedestrian.
Gurney Plaza refurbished all their toilets last year (at least all the ones I had visited) and now are a good standard. And the G Hotel is next door anyway, if you’d prefer to go there. Their ground floor toilet is very nice.
Paragon Gurney’s toilet facilities are just fine.
Midlands Mall (AKA Onestop) toilets are best avoided – but the Berjaya Hotel is next door and their toilets are reasonable, and are on their ground floor – walk past reception and turn right at the end.
Komtar and Prangin Mall toilets are best avoided, but both are joined by overhead bridges to the new First Avenue Mall, where the toilets are nice.
In George Town the obvious solution is, of course, one of the hotels there – E & O, and Traders Hotel being a couple of the better ones.
At the other Tesco, near the bridge, the toilets are not so good. And E-Gate next door is not much better, from memory.
Queensbay Mall toilets are quite bad, with one exception I am aware of – the top (3rd) floor, in the North Zone, near Kamay Furniture (Lot No: 3F-03 & 03A). This toilet is clean, pleasant and airy. It’s worth a five-minute walk from anywhere else in the mall.
If at Penang Airport one wonders if you are not better off waiting until you are on the plane. But as the airport is being refurbished, one hopes that they will provide facilities of an acceptable standard.
Restaurants and coffee shops are hit and miss, with some even upmarket establishments providing very poor facilities. And hawker centre facilities are best avoided if at all possible.
I am sorry that this the best I can provide at the moment. Any other input is appreciated.