Да я вообще не въезжаю в твои сложности...

mysql> create table test(txt text);
Query OK, 0 rows affected (0.36 sec)

mysql> insert into test select '\\\\\\"qqq1\\\\\\"';
Query OK, 1 row affected (0.05 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> select txt, replace(txt, '\\', '') from test;
+--------------+------------------------+
| txt          | replace(txt, '\\', '') |
+--------------+------------------------+
| \\\"qqq1\\\" | "qqq1"                 |
+--------------+------------------------+
1 row in set (0.01 sec)

mysql> select txt, replace(replace(txt, '\\"', ''), '\\', '') from test;
+--------------+--------------------------------------------+
| txt          | replace(replace(txt, '\\"', ''), '\\', '') |
+--------------+--------------------------------------------+
| \\\"qqq1\\\" | qqq1                                       |
+--------------+--------------------------------------------+
1 row in set (0.00 sec)