By using executeBatchDelete api you can clean the records in BO and its child BO.

Sample SOAP request:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:siperian.api">
   <soapenv:Header/>
   <soapenv:Body>
      <urn:executeBatchDelete>
         <!--Optional:-->
         <urn:username>admin</urn:username>
         <!--Optional:-->
         <urn:password>
            <urn:password>admin</urn:password>
            <urn:encrypted>false</urn:encrypted>
         </urn:password>

         <urn:orsId>localhost-orcl-sandbox1</urn:orsId>

         <urn:tableName>C_BO_PARTY</urn:tableName>
         <urn:sourceTableName>ZZ_DELETE_CUST</urn:sourceTableName>
         <urn:recalculateBvt>false</urn:recalculateBvt>
         <urn:cascading>true</urn:cascading>
         <urn:overrideHistory>false</urn:overrideHistory>
         <urn:purgeHistory>true</urn:purgeHistory>
      </urn:executeBatchDelete>
   </soapenv:Body>
</soapenv:Envelope>

Above, sourceTableName is the temporary table that consists of RowID Xref that you want to delete.