If all you have is a 6 wt, then the answer is, yes you can play a chum on it. You have to play them quite a long time though and it really stresses them (not a good thing prior to spawning). If you have access to a 7 or 8 wt, you are better off using that. As HOOK has pointed out, the freshness of the fish is an important factor to consider. If you are hitting old boots in the Stave for example, they don't have the strength and stamina of the fresh fish of the Squamish, so are easier to handle on a lighter rod. You should be able to pick up something like a Dragonfly set (rod, reel and line) 8 wt for under $200. Might be a good investment if you really want to target chums.