Buff, a friend of mine contacted me just now in regards to your question,..
This friend is extremely knowledgeable. He is a specialist in Black Powder rifle shooting . He told me to tell you the following :
Obatex is extremely corrosive , shooting it in your Flintlock will damage your rifle barrel. It causes severe fouling in the barrel as well.
Using the Obatex in the pan will not result is the required high temperatures to burn hot enough cause an ignition.
He is of the opinion using Obatex in your Flintlock is not a good idea at all.
If you can give me the Game Farm /Outfitter contact details I can take the ZAR black powder , locally manufactured here in South Africa by Johan Greyling of JS Gunsmith shop to the farm .