jonpalls post was a good one, just wanted to mention something about practicing and how skill development works: it works on RACKED UP CONSISTENT SESSIONS OF THE SAME THING. So you may feel like in one session you couldnt get the result you wanted, but do the same routine the next day and i think you will find some progress. its almost like the progress happens when you return the next time, one off sessions dont seem to do anything on their own until you do a second session. i know this wasnt an exact answer to your question but i know that when i started approaching skill development with this mindset i started making great gains (applies to everything) i started changing my approach to this after years of not making gains in weightlifting. then i applied this mindset to all my skills and it worked. before i was just doing some lifts, then the next session i would do different lifts and wouldnt be consistent with my routine, things need to be done as a proper ROUTINE. but progress doesnt occur like a linear ramp, its more of a 2 step forward 1 step back thing for example: vocal range. in one month of practicing vocal range your range probably will not ramp up linearly, it will be bumpy like a stock graph, up down up up down down up up up etc. so i am not annoyed if i lose 1 or 2 notes the next day because i understand that the important comparison is in one months time, not today or yesterday.

Great answer, Phil!

Thanks a lot for your answers!
A lot of helpful words.

The one thing that bugs me the most is that the grit gets stuck in the throat (the grunt-sensation). Sometimes when i do high screams I gte the placement right, but as soon as I try to actually sing gritty, it feels like swallowing sand paper. Not very pleasant at all.

and I have this idea that if I grasp the low grit exercise, the rest will pretty much fall into place.
But I can't seem to find it.

Okey, so here's an update:

still no real progress on achieving the low grit sound.
I ALWAYS end up with the choked grunt = ouch.

But I just stumbled over something roday. In one example, Jaime demonstrates a grit that's lika sigh. Pretty breathy, but with the rumbling sensation in the soft palate. And I discovered that I can do this sound.
It's not a pretty sound! but it feels like I'm finding the placement.

It doesnät hurt, although I use a lot of air, so my throat gets kind of dry after a while.

Could this be a way of finding the right placement for the cleaner, non-breathy grit?

I recorded an example of this breathy "sigh" grit.

http://www.box.net/shared/pq874mj8xp

Any ideas or advice is highly appreciated!