that's great, and yea the rubbing of leather against ground is a good static discharge on its own. As long as its tested against electrical hazard, dielectric strength etc to ensure wearer is not harmed from lightning strike. I think they test it in both dry and wet conditions and infuse up to several k V but lightning can go up to million volts and would go through the least resistant (most conductive path) hence why some grounding shoes tend to come with lightning disclaimers.  

 Because the shoes are highly conductive, they can discharge static effectively,  but high conductivity can be paradoxical as it can also create a pathway for other currents (exposed wiring, possibly lightning which has up to 100,000 amps and electrocute someone). Franklin has static sparks transfer from stormy clouds to metal keys to his knuckles through a wet string. 

Typically esd shoes with metallic particles have resistance shields. If you have tested it that's great, if you have not, then many industry standard labs can test for electrical hazard / resistance / dielectric strength tests and others alike. 

Back in the old days, cars tend to have grounding strips to discharge static, but cars also have a metal shield that works as Faraday Cage. Leather shoes, even if highly conductive, would not work like Faraday Cage. 

If you want people to make safe and conscious choice, you can include disclaimer for lightning, exposed wiring, power lines etc. 

I love your shoes. Good luck  @rhizal and hope these helps! ❤️

Cc  @jack - love your childlike enthusiasm and genuine kindness, but try to alive while at it ok?