new Handle:cvar = INVALID_HANDLE;

public OnMapStart()
{
         cvar = FindConVar("sv_cheats");
         
         new flags = GetCommandFlags("host_timescale");
         flags &= ~FCVAR_CHEAT;
         SetCommandFlags("host_timescale", flags);
}

BulletTime(bool:enable=true)
{
          for (new i = 1; i<=MaxClients; i++)
          {
                 if (IsClientInGame(i))
                {
                        SendConVarValue(i, cvar, enable ? "1" : "0");
                }
          }
          ServerCommand("host_timescale %f", enable ? 0.25 : 1.00);
}