Delete contacts from PokeNav in Emerald

[MikaCookies]

I know i can't delete NPC contacts legally, but i don't know how to do it with pkhex.

I need to delete some contacts because I use a bot that makes random encounters for me to get shiny Pokémon and every time I reive a call It froze.

Are any form to do it or is not possible yet?

[theSLAYER]

Probably check pret disassembly of Emerald to see which flags correspond to which trainer (in relation to having received their contact), then manually disable those flags in PKHeX event flag editor 

[MikaCookies]

I am not sure to know how to do that...

[BlackShark]

The flags from 0x15C - 0x1A9 are used for rematches. However there is also rematch data in the save at 0x9CA (Block 1).

You can try if resetting those flags is enough, else you would also have to erase the rematch data with an hex editor.