[Tev]

Originally Posted by Geminex

The only question I can come up with now, is “How are you supposed to get it off?”, but I’m sure there’s other downsides to coating the world around you in liquid glass.

I'm not sure, the article only had this to say about it's longevity:

In the home, spray-on glass would eliminate the need for scrubbing and make most cleaning products obsolete. Since it is available in both water-based and alcohol-based solutions, it can be used in the oven, in bathrooms, tiles, sinks, and almost every other surface in the home, and one spray is said to last a year.
Liquid glass spray is perhaps the most important nanotechnology product to emerge to date. It will be available in DIY stores in Britain soon, with prices starting at around £5 ($8 US). Other outlets, such as many supermarkets, may be unwilling to stock the products because they make enormous profits from cleaning products that need to be replaced regularly, and liquid glass would make virtually all of them obsolete.