You're right Athena, I believe that is what Jin Yong *meant*, but his writing doesn't clearly reflect that. So I think you are just fixing his problem for him.
What I mean by "writing doesn't clearly reflect" is this: right after it says 但说到功力修为，自比他二人深厚得多, the next statement in the same passage is 一股大力冲过来. IMO this strongly suggests that it was Li Mochou's raw force that cleared Xiao Longnu's acupoint.
But I do in fact believe that Jin Yong meant Li Mochou's more profound grasp of internal cultivation is what helped clear the acupoint. I just don't think Jin Yong's description communicates that well.