Salt... Check this out. I was curious myself and so did a play on Fusarium words. Especially read the last two sentences. It tells how they destroyed the fusarium with seed drying.
https://www.researchgate.net/publica...ersici_race_J3
This publication recommends rotation of plants every 4 years to help with the fusarium.
http://www.aces.edu/pubs/docs/A/ANR-0797/ANR-0797.pdf
Here a good one from Clemson University. Just scroll down to the Fusarium Wilt section and at bottom of page there tables for tolerant types of tomatoes for some of the different diseases to include Fusarium.
http://www.clemson.edu/extension/hgi.../hgic2217.html
Personally, I think your seed probably safe after what I been reading. I'd grow your seed in a heartbeat. You ferment, you dry and maybe if you want to do an extra step of protection do the Cole_Robbie method too with the oxy clean.