I just recently finished a raw shrimp cycle.
It took about a month for my 10 gallon to cycle. The first day or two, it stank a lot. Then, the smell more or less disappeared. I kept the shrimp in there whole process, checking the water parameters once a week. When the ammonia was 0, nitrites 0 and the nitrates about 80, I did a massive (70%) water change, and I was done.
Towards the end, I got really impatient, because to me it seemd like nothing was happening to the nitrates, so i ended up sprinkling fish food in once daily for three days, then stopped when the ammonia spiked, followed by a nitrite spike, then finally the nitrate.