[BHaType]

This calls 3 functions at once but you can find the signature and only call "CStringPool::FreeAll()"

Code

PHP Code:

#pragma semicolon 1
#pragma newdecls required

#include <sourcemod>
#include <sdktools>

#define ADDRESS(%1) view_as<Address>(%1)

Address g_GameStringPool;

public void OnPluginStart()
{
    GameData data = new GameData("gamedata");
    
    g_GameStringPool = data.GetAddress("g_GameStringPool");
    
    #if defined LINUX
        g_GameStringPool += ADDRESS(0x13029F0);
    #endif
    
    delete data;
    
    RegConsoleCmd("free", free);
}

public Action free ( int a1, int a2 )
{
    /* 
    
    FreeAll();
    PurgeDeferredDeleteList();
    CGameString::IncrementSerialNumber();
    
    */
    
    Handle hFPC = CreateCall (g_GameStringPool, 7); // linux 7 - 9 idk
    
    SDKCall (hFPC, ADDRESS(g_GameStringPool));
    
    delete hFPC;
}

Handle CreateCall ( Address pInstance, int offset )
{
    StartPrepSDKCall (SDKCall_Raw);
    PrepSDKCall_SetAddress (Dereference(Dereference(pInstance), offset * 4));
    PrepSDKCall_SetReturnInfo(SDKType_PlainOldData, SDKPass_Plain);
    return EndPrepSDKCall();
}

Address Dereference ( Address ptr, int offset = 0, NumberType type = NumberType_Int32 ) { return ADDRESS(LoadFromAddress(ptr + ADDRESS(offset), type)); } 


Gamedata

PHP Code:

"Games"
{
    "csgo"
    {

        "Addresses"
        {
            "g_GameStringPool"
            {
                "signature" "g_GameStringPool"

                "windows"
                {
                    "read" "10"
                }
            }
        }
        
        "Signatures"
        {
            "g_GameStringPool"
            {
                "library"    "server"
                "windows"    "\x55\x8B\xEC\x51\x8D\x45\xFC\xC7\x45\xFC\x2A\x2A\x2A\x2A\x50\xFF\x35"
                "linux"    "\x55\x89\xE5\x53\x83\xEC\x14\xE8\x2A\x2A\x2A\x2A\x89\x04\x24"
            }
        }
    }
} 


I didn't check because I don't have csgo