How to battle the incapability of 'unreading' something, or, How to prevent from reading offensive material?

Offensive in the eye of the offended.
In an earlier question today, and in others in the past, it was suggested to not read something that you find offensive.
If I read the sentence: “She was devouring one kilo of boiled carrots.” it is already too late…, I am close to puking.
The NSFW tag acts as a kind of !SPOILER ALERT! I think, but how can one ‘unread’ something that has already been read in case the offensive text is in the header of the question (on the main page of Fluther)?
Also in threads it happens that someone reads a certain description of a certain act; again the damage has been done the moment one has read it.
How can we prevent this from happening that is if we should want to prevent it?
Any ideas, fellies?