Not wiping group ranksBug

I use this PlayerRankings/betterchat with kits/perks as permission on some ranks. I have to remove all 8 oxide group every time i wipe. Even if Playtime is set to zero. They get [old rank] + [1st rank] if i dont delete all oxide groups.. 

Have to do this every time:
oxide.group remove private
oxide.group remove corporal
oxide.group remove sergeant
oxide.group remove major
oxide.group remove lieutenant
oxide.group remove colonel
oxide.group remove captain
oxide.group remove general

then enter all permissions all over again...

How to fix?

The issu is when i wipe ranks, betterchat still hold better rank [TAG] from before wipe and oxide group....

Merged post

can not find any commands to remove ALL players with one command
if you have like 100 players, its hard to remove all
understand? i have 1 mod called nuke target (adv. airstrike) this should only players from 40 hours playtime have.... and so one....
i use like 5 mod to this now, also custom KITs bases on rank
so what i did last time was removeing all 8 groups by commands. then set up all permission again... like 8-9 different plugins permssions, different from default. all this manually, if i dont delete oxide groups i can hold this settings after wipe
If you only grant permissions by adding players to groups, you can safely delete oxide.users.data when wiping. There is saved in which group(s) players are.
But be careful! You will lose all individually granted permissions to players.
In response to chadomat ():
If you only grant permissions by adding players to groups, you can safely delete oxide.users.data wh...
the file in data folder? so you understand me correctly. I dont want to delete groups just remove all players from all groups.... ?!