I hope this isn't too far off the subject, but as long as we are talking about innovative traps, I have caught several muskrats alive in colony traps set in the following manner.
First off you need to get the muskrats in the habit of eating carrots. If they haven't been exposed to them it can take them a couple of days to figure out what they are. Once they realize they are food they will seek them out.
Mike M. and I discovered this several years ago while experimenting with various traps on golf course ponds in Sumner Washington.
We found that we needed to scatter carrots around the edges of the ponds a few days before setting the ponds in order to condition the muskrats into eating carrots.
One set that worked was to take a colony trap and set it on a gently sloping bank with one end of the trap in maybe an inch or so of water. Naturally the back door of the trap is in the closed position due to gravity. But I would prop the front door (the end that is in the water) with a toothpick size stick. I would prop the door open maybe three inches so that when the muskrat walks into the trap his back would lift the door just slightly and the stick would naturally fall over and the door would close behind the muskrat.
This set actually worked great, the drawbacks however are that you then have to take the time to dispatch the muskrat, and because the trap is essentially a live trap which requires a 24 hour check, whereas a killing colony trap may be checked every 72 hours.