Mojo Mud is Tungsten-based putty designed by guides for cold water use.
If you are a long-time split-shot user then switching to mud will take a little getting used to. But this is the best mud on the market. I've tried others (Loon) and there's no comparison. Mojo is tops. Its sticky but no too sticky. You'll firgure out the best way to attach to your leader (long football shape).
Here's a little trick: Lots of fishermen don't like havinng to open the little case that holds the mud, then put it back in their fly vest every time they want to use it. Its a pain as all u want to do is fish not fuss with your tackle. So...Take a small amount of mud and stick it on the side of your reel. Then when u need more of it you have it readily available. Just take a little off and apply to your leader. When your fly is getting hung-up on the bottom too much you just take a little off your leader and stick it on your reel. No more having to open, close, reopen and then put away the carry case of mud. Simple.
Not a big fan of this stuff but when you're in a bind it works. There are a couple of major flaws in my opinion with the mojo mud. It tends to slide around on the line, doesn't really want to stay in one place. The amount of 'mud' that you get is pretty small especially in relation to the package that it comes in. You have to harden the mud in the cool water in order for it to work halfway decent. Also, I never know how much to use. With split shot I know generally how deep 1 or 2 are going to get me but with this it is a real guessing game. This sinks very quickly with a relatively small amount on the line. I'm sure it's a fine product if you have the time and patience to dial it in.
I bought this stuff because I tend to fly through splitshot and figured this would last a bit longer. First, the packaging. I see a big circle and an average sized cube in the picture, but when you actually get it, the cube of putty is pretty tiny. You NEED to cool it off in the water to get it to harden, but even this results in launching putty across the water. My main problem with this stuff is that, on most waters I can tell "I need 1 AB weight here" or "this water looks like 1 AB and a BB of weight" With the puddy, i have absolutely no clue how much to use. It doesn't feel heavy but the tungstun has a much higher sink rate. I'll keep this in my bag for when I run out of weight, but i dont see myself using this day in and day out. Maybe I just need to get used to it