How to properly move a part between OLBs with TCL?

I am trying to clean up some old libraries i.e. move unused parts from active.olb to unused.olb. The code is presented below. Everything works pretty well except that there is something hanging inside active.olb that prevents creating a part that was there before. E.g. if PART_123 was moved from active olb to unused.olb, I can not create PART_123 again. If I look inside active.olb file, PART_123 is still mentioned, despite not being shown in the lib tree structure. I guess I am missing some cleanup in my code, but I can't figure what exactly, so I am asking for your help.

set lSession [DboTclHelper_sCreateSession]
set lStatus [DboState]
set lNullObj NULL

#Provide the location of olb FROM which package should be copied.
set lSourceLibPath [file normalize {D:\ACTIVE.OLB}]
set lSourceLibPathCstring [DboTclHelper_sMakeCString $lSourceLibPath]
set lSourceLib [$lSession GetLib $lSourceLibPathCstring $lStatus]

#Provide the location of olb TO which package should be copied.
set lDestnLibPath [file normalize {D:\UNUSED.OLB}]
set lDsctnLibPathCstring [DboTclHelper_sMakeCString $lDestnLibPath]
set lDestnLib [$lSession GetLib $lDsctnLibPathCstring $lStatus]

#parse all packages in the olb
set pkgIter [$lSourceLib NewPackagesIter $lStatus]
set pPkg [$pkgIter NextPackage $lStatus]

while {$pPkg!=$lNullObj} {
    set pActualPkgName [DboTclHelper_sMakeCString]
    $pPkg GetName $pActualPkgName
    $lDestnLib CopyPackageAll $pPkg $pActualPkgName $lStatus
    $lSourceLib DeletePackage $pPkg

    puts [DboTclHelper_sGetConstCharPtr $pActualPkgName]
    set pPkg [$pkgIter NextPackage $lStatus]
}

$lDestnLib MarkModified
$lSourceLib MarkModified

$lSession MarkAllLibForSave $lDestnLib
$lSession SaveLib $lDestnLib
$lSession RemoveLib $lDestnLib

$lSession MarkAllLibForSave $lSourceLib
$lSession SaveLib $lSourceLib
$lSession RemoveLib $lSourceLib

DboTclHelper_sDeleteSession $lSession