That site is somewhat incorrect. The sheriff, in Iowa, does not perform the actual set out. It is, by statute, required of the LL to provide all the manpower to set the deadbeat's belongs on the curb. The LL has no further responsibility for the deadbeat's property beyond this. The sheriff is only present to keep the peace.
Yes, the time frame may vary, but typically you won't get the sheriff to appear for 3 days. You must schedule the set out to coincide with the sheriff's scheduling. But yes, by statute, the court decision is effective immediately.
The whole process (from filling to set out) should take 21 days or less.