Using shrimp method to help tank mature(cycle),can get smelly, as shrimp rot's and is consumed by bacteria, but water changes can aleviate the smell, and not slow the process to any degree.
Just take care not to change,remove,filter material for first few week's.
Have used this method a few times and found it is very easy to use too large, or too much shrimp.
A couple small cocktail shrimp in 30 gal is about right.(too much, and nitrites portion of cycle can go on forever).
My sister once called me to tell me this method was running her out of the house.(smell)
When I asked further,,she said she had tossed two Jumbo shrimp in 20 gal