Dbcopy allows me to backup but over several weeks the destination folder get large

I was thinking out using Rsync

My GW is on a volume (ext3) called gw
I've added another volume gwbak

I'm currently doing a rm -r /gwbak to delete the backup once a week

This takes some 4hours to remove and dbcopy

I was thinking of using rsync remove files no long in the source

ie. rsync -av --delete-after /gw/ /gwbak

then use DBcopy to copy the live files

dbcopy -p /gw/gwpo /gwbak/gwpo
dpcopy -d /gw/gwdom /gwbak/gwdom

Would this safe (obviously need to make sure not mixing up source & destination !!

Any pitfalls ?