The yells on Asura aren't nearly as bad as people make them out to be. Sure, sometimes you'll run into a random yell-fest where people want to spam politics, science, or talk other trash, but that isn't as common as it's made out to be. What you really have to do is be pro-active on the black-listing of people that want to sell (read: scam) JP leeching. If you see someone yell anything about "500-2100", just block them right away. As far as the RMT yells go, when they have gibberish names, I find it easiest to just... for example:
Name is: Aeonidsnfuasdfnasdnf. Type /sea all aeo. Click their name like you're going to whisper them and then use the arrow keys to remove "/tell" and add "/blacklist add" in front of their name.
My biggest tip though, is for people with mules. Just block yell when you're on a mule. You're not going to miss anything important. If someone is giving away a Kraken Club, there is a 0.000000000% chance that you would be the one they are giving it too. Turning off yell, on mules, allows you to not have to keep your blacklist constantly up-to-date.
Another tip is to just avoid standing around in towns. Be out doing something. If you must be in town (say you have to camp the crystal ephemeral moogle while crafting or something), just keep on the blacklisting. SE doesn't ban RMT as quickly as they should so it helps.
Anyhoo, this wall-of-text is kind of pointless as anyone that actually uses blacklist already knows this stuff and those that don't use blacklist and yet still complain about yells are asking for it.
I just really dislike Asura's bad rap.
Following image of Final Fantasy XI troll:
It's bad Aps.