This thread is crazy.
I don't know if we can access the third attention until death, and even then, I don't know if we can access it. I feel this is something the Buddha either achieved or went beyond, but the third attention now. I primarily focus now, on the here and now, and some dreaming in the second. But I don't concern myself too much with the third attention. I know if I 'think' I experienced it, it is probably not 'it.'
Also I would say Jahn has shared experiences, Juhani - not too much.