By 2006/2008 the V6 trans problems were pretty much solved for the most part. My plan of attack when I bought my 130k TL Type S was a complete 3X drain and fill when I first got it, and then 1x D/F with every oil change after for the next handful of changes and then every other oil change after that.
I do 1oz of LG Red per Qt of fluid out/in.
I don't change the washer every change though, and no leaks. If they start to seep, I change the washer, otherwise I don't.
My 03 Accord V6 gets pretty much the same deal, every other oil change, but its the '[censored]' transmission, so I fully expect to have to replace it again (it was replaced at 110k), if I keep the car much longer (220k on it now)
FWIW I was speaking with a pretty highly regarded Honda trans guy in these parts and he recommended for the V6's, every 10k do a drain and fill, lines up pretty well with what I was already doing.
Also, if you do any reading around the net, you will see people talking about replacing the pressure switches. I'm still undecided on if it is a good plan or not. I've done mine, they're easy and not terribly expensive, but I don't have a lot of hard data to back up the claims.