According to Gibco-Invitrogen, their oligofectamine is not supposed to be used for RNAi, but rather for antisense oligos.

However, there's a paper that describes the use of oligofectamine for transfection of macrophages (which are usually difficult) with siRNA.

Does anyone have any experience here?

Invitrogen also has a protocol for transfecting sirna into hela cells with oligofectamine on their website, im my experience, while it does transfect, there are better transfection reagents for sirna available
Hope this helps