My Dad was deployed to Vietnam during the war where was heavily sprayed with Agent Orange. He gets strange symptoms such as mild seizures/tremors with chills and extreme fatigue still to this day. Any suggestion?

1. These are the following things you could try:
a. Terrain Protocol. Run first time on Remote. If your dad has bad herx symptoms, then pause generator for a day or two then resume. Run follow up sessions using contact mode. Run additional programs for liver and kidney support during detox. If he has amalgam fillings use Terrain-(minus)Mercury preset. 

b. Try Activated Charcoal tablets, say one tablet a day for a week, then take a break for a week or two and repeat. During break take mineral and vitamin supplements. 

The 90 Essential Vitamins & Minerals Part 1 of 2 
https://www.youtube.com/watch?v=qMYIJlmeSFM

c. For additional parasite treatment consider Pure Gum Spirit 
Kill PARASITES using Pure gum spirits of Turpentine! 
https://www.youtube.com/watch?v=JwotJoPS5Zo

d. Posts re neurotoxins:
https://www.spooky2.com/forums/search.php?keywords=neurotoxin

2. Perhaps you might try running the frequencies contained in the file posted at :
https://www.spooky2.com/forums/viewtopic.php?f=32&t=8600&p=80816#p80816

Attempts to help the body get rid of harmful substances using frequencies, is a work that should span a longer period of time.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=18&t=8994