Playing Loose-Agg successfully requires being able to read players and situations very well. It's difficult to do, particularly online. The only time I would consider doing it would be if I can tell another player is doing so. If I know someone is calling as wide as say 9 6 suited, then playing J 9 off against him is fine. Ultimately though, you need to get people folding to play LAG.
Otherwise playing loose-aggressive doesn't work out. You are playing hands that are generally not winning hands. It's that simple.
There are some ways to intermingle LAG plays into TAG style, and I think it actually enriches your play. Refining your 3-bet range from the blinds to include hands like AJ/A10 can be good. These are hands that generally winning hands but hard to play out of position sometimes. 3-betting those will generally get a fold, are usually getting flat called by hands that are behind, and usually getting 4-bet by hands that are ahead (AQ being the exception). But it also amps up the frequency in which you 3-bet, so might help you get called or 4-bet when you have KK/AA.
Similarly, once every 50 hands or so, it's not bad to play a "bull shit" hand. If you get lucky and hit, people don't give you credit for that hand, and when you do show, it makes you that much of a scarier player to play against.