Perspective
Whilst what Bus Junkie says can and does happen. The backpacker district, is a pretty rough seedy place in my opinion, so if you venture just a little more upscale rather than squatting on the street, you should have no problem with toilets or soap. Etc
Just check trip advisor and look at the top 100 resturants in Ho Chi Minh, I don't think you will find those complaints..
The few roads of the backpacker area itself are seedy at night, but that is why people go there. The park, I'm sure you know, is not a bit seedy during the day. Sitting within sight of Ben Thanh market is a very nice family park with public toilets, that so many don't use.