Here are instructions and photos.

http://www.matthewsvolvosite.com/for...php?f=1&t=8767

 

Yes the IPD style method would be a "flush". You are just using the transmissions pump to push the fluid out. I found out water softener drain hose is just the right ID to fit snugly on the end of the cooling line on mine.

The horror stories are from having a neglected transmission power flushed. I worked in fleet maintenance and our rule of thumb was if the transmission hadn't been serviced in 100K miles to leave it alone. Most of our fleets turned their cars back in around 60-80K but we had some that drove them till the wheels fell off. From our experience once a vehicle crossed over 100K and hadn't been serviced if we allowed a driver to have it done we saw a much higher incidence of failure in a short period of time. I lived it, I saw it and I believe it to be true. That 100K isn't anything scientific it was just our rule of thumb. You also can't factor in how a person drives and the harder you drive a vehicle the sooner you should swap out fluids. Only a driver would know if he (or his 18yr old son, sorry dad) has been harder on the vehicle.
I think at some point the clutches inside the transmission get so worn it's the grit in the fluid that's keeping it working. I try to keep people who haven't done one and have high miles from doing it. And there is always an exception. If it's already slipping and the fluid looks like crap then flushing it can't really hurt much. It might be a cure and the downside is it might be the straw ... you might lose what little operation you have.

Now having said that I bought a very abused and neglected 850 and the fluid stunk and was black and I just couldn't stand it. It didn't seem to be slipping and I finally couldn't stand seeing that fluid. I did a DIY flush somewhere around 270K and I'm sure it was the first. I don't view it as a smart thing to have done but I couldn't stand the smell or color (I'm OCD). A year later It's still shifting fine and the fluid is still looking good.

It's like a timing belt. A very few will fail early, most will easily go their recommended service life and a little extra and some will surpass their service life by double or triple with one more day being a gift from God if it doesn't break !!

If you have your transmission power flushed every 50K since new, wonderful. If you do it yourself by drain and fill or flush great.
If you buy it used and have no history the drain and fill is the safer way to go but the DIY flush IMHO gets more of the old fluid and contaminants out and is safe also.

If you have no history I'd stay away from the power flush. That's my recommendation from experience with real world results and most people on here seem to agree from what they've come across.

 

Since I had my tranny replaced, I have replace the fluid once with the "drain and fill x3" once. In 5,000 more miles I think I'll try the flush method. I do have a spare tranny in storage.