I am the last person to get information on TC plants from..but as far as buying corms from Going Bananas and being concerned about introducing problems in to your garden....I have no concerns...having visited Going Bananas on many occasions and through numerous conversation with Don Chafin I have concluded that he is incredibly thorough about sanitizing plants...check out the videos (requires "Real Player" on the following link:
http://tfphotos.ifas.ufl.edu/VFLrealfiles.htm
Go to Don’s video:
Banana corm cleaning techniques - Don Chafin................................(04:51 mins)