Sowing Dead Lawn with Cover Crop

Hey there,
I'm out in Oregon, short dry summers, long wet winters.
My current lawn was light forest last November, and the landlord ripped it all out. Didn't plant grass seed, random stuff just sprang up. Since then, I've mowed a handful of times, it's pretty much brown straw now.
I bought some buckwheat seeds the other day. Is it a fool's game to simply throw them out there, rake a little, water a little and let it be? Or do I need to aerate and get a de thatcher? Trying to go for least effort possible, if you couldn't tell. Thanks!

I actually did something like this about two and a half weeks ago (I'm in the Puget Sound area, so less hot and more drizzly than you.). Our grass was tall (6-8 inches) and green, but we had a bindweed problem so we planted buckwheat in hopes it will inhibit the bindweed. ANYWAY, we laid down the buckwheat seed, mowed the lawn so the clippings fell over the buckwheat, put down a little more buckwheat seed for insurance (my husband wanted to), and then sprinkled some duck bedding over it (not very thick, and many areas didn't get any). We kind of watered twice, and we planted it during the last heatwave that was here (and then we had a few rainy days, and now it's hot/dry again). Almost all of the buckwheat sprouted and is growing happily. The stuff that got more grass clippings is happier, and there are patches where there's no buckwheat, probably because it got no coverage.

I'd say go for it! If you can give it a watering or two during these next hot days just to get it established, that should help. And, the more clippings or other organic matter you can get over it the better. But, you should get some growth, one way or another. Aerating shouldn't be necessary at all, but getting some sort of matter even thinly over the seeds should help a ton.

I hope that helps! Good luck!

Here's some pictures of my buckwheat growing in the lawn. I sewed the seeds pretty thickly because they were a year old and I really wanted to outcompete the bindweed, and I honestly didn't think I'd have this success ratio!

I checked my records and this buckwheat was sewed on July 20th, so that's three weeks of growth with only two waterings, but we had an odd rainy/cool front last week.

Raking, sowing seed, racking it in and rolling it should ensure establish a good cover crop.   If you are looking to smother the weeds and fix some nitrogen I would recommend ordering some subterranean clover seeds,  It is a very pretty ground cover and re-sows it own seeds.  Sub-clover is an annual so in the dry summer it will all die back and you need to rake it in order to keep it going.  That is just one suggestion, there are lots of clovers and diversity is always better.  Alfalfa can be used as a cover crop and will last through the dry summers.