time from on it leeching ammonia is 2-4 weeks using a under gravel filter and 4-12 weeks using a regular filter. Doing massive water changes won't make it happen faster, it will just wear the buffer out quicker. The soil is loaded with ammonia and leeches out and that's that with the soil.
Thanks for the information. I finished planting it today, and added the one rock I wanted to add covered in moss. This stirred the substrate and went from Tea to black again. I did two 50% water changes, and those will be the last water changes until the ammonia stops leaching.