Look at the sole of this bathroom / household / Hawai slippers.
Its "designer" must have contributed to the financial well-being of orthopaedics and pharmacists at great risk to life and limb of people.
You wear a pair of these and step on water on smooth floor (not the rough road is what I mean) and hey presto!, you are horizontal on the floor. The sole has pyramid shaped depressions. When your weight falls on the slipper, the air trapped in the depressions must somehow escape. When it does you become a "hovercraft" and the foot does not get any grip.
So, before you buy a pair of slippers (What a perfect name in this case!), watch out for the sole. Avoid those with this feature like the plague! If you have a pair at home like this, cut them and throw them away. If I am not mistaken, even Bata sells a model like this, in India.
There may be other such designs. If you look at the soles, you will be able to see if air could be trapped somewhere.