When Forgetting What to Say in Japanese

In Japanese, when you somehow can't come up with the word you want to say, you'll say "アレ" like this:
「アレどこいったっけ、ほら、紙切るやつ…」
This is like "Where is THAT, you know, something to cut paper (1)..." in English, I think. (2)
"あれ" means "that", indicating something over there or something someone said before.
In this case, I like to express it in katakana for a little bit unusual use. (3) 

But if this use of "アレ" goes too far, it becomes like how my mother said one day:

「アレをアレするのはさすがにアレでしょ～！」

This might be translated as: "It's obviously THAT to do THAT of THAT~!"
You may not understand what she meant (4), but before she said it, I said "Don't talk about the ending, I'll read it".
So she meant that it's not good to reveal it.

We laughed how even though she forgot things, while all of us could understand what she meant by "アレ".
I think this is a example of how context-dependent Japanese is, or this is very usual in other languages?

1) This is a fine place to cut the sentence, but most of the time when someone forgets a word, for example, in that context, they would say "something to cut paper with..."

2) I do see this kind of wording frequently in chatrooms. If you want a sentence that would be structural, you can use "I believe in English it means "where is THAT, you know, something to cut paper with..."

3) I wasn't entirely sure what you meant by "unusual use." I know that Katakana can be used as emphasis like with capitals in English. Is that what you were going for?

4) There are times where "of course you" is acceptable, but if used the wrong way, it can be viewed as being arrogant. In most cases, "of course you [negative] can be viewed as the speaker mocking the listener. When a friend asks for advice and the answer is very clear-cut, "of course you should [advice]" is acceptable. When an accident-prone friend crashes into a glass door, "of course you would crash into a glass door" would often be said.