CREATE TABLE PERSONS 
(
...
    PERSON_COMM   CLOB,
...
)

CREATE TABLE OBJECTS 
(
...
    OBJECT_COMM   CLOB,
...
)

insert into PERSONS
(
    ...
    PERSON_COMM, 
    ...
)
values(
    ...
    :PERSON_COMM,
    ...
)

insert into OBJECTS
(
    ...
    OBJECT_COMM, 
    ...
)
values(
    ...
    :OBJECT_COMM,
    ...
)

        cmdInsertPerson = new OracleCommand(constants.InsertPersonSql, OraCon);
        ...
        cmdInsertPerson.Parameters.Add("PERSON_COMM", OracleType.Clob,  250 , "PERSON_COMM");
        ...

        cmdInsertObject = new OracleCommand(constants.InsertObjectSql, OraCon);
        ...
        cmdInsertObject.Parameters.Add("OBJECT_COMM", OracleType.Clob,  250 , "OBJECT_COMM");
        ...

void AddObj(HashTable ht, ...)
{
    ...
    cmdInsertObject.Parameters["OBJECT_COMM"].Value = ht["comm"].ToString();
    ...
}

void AddPers(string comm, ...)
{
    ...
    cmdInsertPerson.Parameters["PERSON_COMM"].Value = comm;
    ...
}