Distracting ants from old food sources

I've got a pecan tree with an ant trail running up the trunk.
Presumably the ants (argentine variety) are farming aphids or
something up in the crown.

Initially the ants were attracted to a bait station hung on
the trunk, but after a failed experiment in bait recipes they
lost interest. I've since replaced the bait and station, but
they haven't shown any interest, trailing past the new bait.

I'd like to distract them, even if only temporarily, from the
old pheromone trails in hopes they're re-explore and discover
the new bait station. 

I'm thinking about simply coating the trunk with dish soap
somewhere above where the bait station is located. However,
I don't want to drive them off the trunk entirely. There
are many alternative paths for ants to reach the crown via
nearby trees which are entirely out of my reach.

Thoughts and stories would be most welcome....

Thanks for reading,

bob prohaska