Ummmm.... I'm fairly sure that directly updating the SAP database with an update like that is a violation of the SAP license agreement, and will void your warranty from any type of software support from SAP.
You should instead use the appropriate DI API objects (Such as SAPbobsCOM.BoObjectTypes.oItems) to perform this action. Using the DI API object should also "clean up" everything else in SAP as well, so no worries about "side effects".