I used a large 3-4' landscape rake a few weeks ago on this hybrid bermuda lawn, It raked pretty easy, It was all the walking that killed me. Took 2 of use 6 hours to thatch and scalp down 12,000 sqft. I forgot to get after pics.
I have not found any thing better than a rake . If the lawn is real dry you can use a backpack blower to blow into piles on a tarp. I think its just as fast and does a cleaner job to rake it up by hand.
Many times, a pushblower will work, also. One of the helpful tips, is to let it dry a bit before picking it up. So, if there is a wind blowing that day, start on the end or side toward where the wind is coming from. That way, if you have help, they can work behind you a bit, and you can have a margin between you to help it fdry a bit.
After running the power rake over it,I take my trimmer around the edges to pull any loose stuff and leaves away from the fences buildings and beds. I will also run the trimmer along the walks to edge them quick. I then take the hand blower and blow everything farther from the edge. I blow out any tight corners and blow off the walks. Then the mower to pick everything up. I law out some tarps at different spots to dump on because the catcher fills up fast. Usually takes two passes. finish with the blower again just to tidy things up and clean off the walks again.
There is no substitute for the Walker when it comes to picking up your debris from thatching/dethatching. BTW true dethatching is a very destructive process that would even stop the Walker but thats another story.
This spring time lawn grooming ritual is a big moneymaker up here and I have perfected the art so to speak. There is very little manual labor of walking around blowing into piles or tarps. You don't have to use a Walker but you sure do need something with some vacuum and a good sized collection system. I have seen over 100 bushels come out of a 10K lawn. People really like the results and I'm lookin forward to goin out again.