a cane
棍 centers on a long, sturdy stick used for support or as a tool: a cane or walking staff.
棍 combines 木 (tree/wood) with 昆, which likely contributes the sound. The character originally referred to a wooden staff or club.
A wooden (木) stick that looks like it could be used by a group of people (昆 suggests a swarm or group) as a cane or staff.
For コン, imagine a con artist leaning on a wooden cane: con -> コン, and the cane is made of wood.