I don't think he was suggesting that. Since the adjective for which you are seeking a substitute has no real meaning that is not carried equally well by an exclamation point, there is no need for a substitute. Anyone who grew up in a time when that adjective was not in common use, has no problem expressing themselves without it. Someone who's never known a time when that adjective hasn't been a part of the general lexicon, is probably a juvenile by definition.
However, to help you find a substitute, how about "freaking?" Oh--never mind--that might be politically incorrect, since it might disparage freaks, and thus discourage diversity. Well, we'll just have to make up a new one... Let's see... How about "frixing?" That might do, since it doesn't have any real meaning either, but as soon as you start to explain for what you are using it as a substitute, people may just turn and say, "Silly rudeboy! Frix are for kids!"
Furthermore, and apart from the fact that the internet encourages colloquial language, the internet spawns its own cant, as is visible here everyday.
The idea is that rather than resorting to crude obscenities, try to develop the ability to articulate what you mean. When you resort to obscenity, you betray your inability to ariculate your mind. This is the real reason why vulgarity is seen as juvenile. What it means precisely is that the one who uses vulgarity is undeveloped.
Honestly, the best suggestion to 1rudeboy is to try to learn the ability to articulate what you think or want to think. That struggle is rewarding in itself as it develops one's awareness of himself. Good luck.