Hi beachin3,
I don't know about there is MA. but here in Maine the color dye is added to the clams. Bait shop here can not sell clams unless they are colored. DMR says it keeps humans from going to bait shops to purchase clams to eat
As for the smell the clams I've used had no bad smell (only smelled like a clam).
If you get a chance tell me how you fish them there. I have a friend that only uses clams after a sea storm (or the seas just turned up in good shape). He claims that's the best time because clams & co hogs have been turned loose by the seas so using clams works best. He catches some pretty good fish so i guess there is some truth to it. He just casts the clams with as light a weight as he can and lets it roll in with the waves.