Hi,
The 'use egress interface IP' option will suffice. If it is nto working, I can think of 2 reasons:
1. The packets are actually exiting through a different interface and not eth0/0. Review your routing configuration and ensure the route points to e0/0.
2. Traffic is using a different policy. You can enable 'logging - at session beginning' on the policy and check if the traffic shows up there.