How much dechlorinator for Bathtub soak of Manzanita Root?

I picked up a nice Manzinita Root for the 75 gallon Angel tank and want to know 1) how long or should I soak it in chlorinated water to kill possible bacteria or parasites that can cause disease to fish? and 2) after that soak how much Prime Dechlorinator should I use and how long should I soak the wood to get rid of the chlorine?

I am thinking tub to be 200-300 gallon or standard sized tub.

Main reason for soaking is to remove tannins and to remove any harmful bacteria or parasites.


Thanks,
Dave

Well if one drop is for 10 gallons then 200 gallons need 20 drops