Quick way to clear space on iPhone without any external app

I always face space crunch issue in my iPhone, and uptil recent past, I used to clear the space using an external app downloaded from app Store. But recently I came across a much better way of clearing space. It is through the inbuilt iTunes Store app of the iOS. Since this is pre-installed app on iPhones, so there is no need to install any other app. And clearing space  using this app, works more efficiently too. Actually, clearing space is not the purpose of this app, but somehow it works. It works when you try to download some large movie file from iTunes store, and you don't have enough space for that in your iPhone. It then gives a pop-up message and then goes to clear the local temp and cache files taking space in iPhone. Below is the steps I am detailing one by one:-

1. See the initial screenshot above, which shows my phone having just 63MB space left.
2. In the next step,  I opened the iTunes Store app. 
3. In 3rd step (screenshot below), I open any movie of fairly large size, much larger than the suspected empty space eaten up by temp/cache files. In this case I chose a movie of size of about 4GB
4. And then you have to click to download /buy the movie. Don't worry about the price of movie. It will never be able to download due to it's large size, so no chance of the money getting deducted. In my case though, I have no credit card connected to my account.
5. After choosing to buy the movie, it will show this pop-up given below, which tells that there is not enough space on the phone, for this movie to be downloaded.
6. Just click OK, and that's it!! Come out of the app. iPhone automatically starts clearing space taken by all major apps one by one. It removes temporary files stored by most apps. You can see the "cleaning" word written below some apps, while the process is on. After 2-3 min. check back the available space again in the settings page. The space must have increased. In my case, I was able to reclaim over 900MB of space.

 Note: This might be a temporary hack, and with further upgrade of iOS, it may stop working. But with the latest iOS version 9.3.2, it works pretty well.