I used it last winter in a TrynEx single stage hopper. I had treated it myself at 8 gal/ton. I have a vibrator on my hopper, had to have it for plain salt, if it was at all damp it would not feed otherwise. The Magic salt went through a bit smoother than untreated ever did, I upped my travel speed to get the same application rate. I'll be using all Magic salt in the hopper this year and we're now looking into a small vee box which will get loaded with Magic as well. I'm still looking for a pump that I can drive off the feed auger on my undertailgate spreader and apply Magic to untreated salt as it goes through the spreader.
I ran the vibrator with the Magic mix. Never thought to try it without the added help the viberator gives. Since the spread rate is determined by the auger flights on the spinner shaft in those units if you keep the auger supplied you get a more uniform spread so I hit the on switch and then the button for the vibrator and just GO!
Our spreader is a Snow-Ex, made by Tryn-Ex. If you can find a dealer for them you can get the vibrator and mount it on whatever brand spreader you have. The Tryn-Ex is the same spreader that Curtis sells and is the same as the old Grotech brand as far as I know.
Incidentaly, with the vibrator we can spread sand through this unit as long as it has no stones of much over 3/16" or so. Anything bigger than that and they jam the feed auger and are a real ***** to get out.
We don't have one of the newer swing-away models. We've got two Buyers tailgate salters that slide into the receiver hitch. We bought them just before the swing-away types were everywhere to be found.
Anyhow, we don't need a vibrator to spread salt. However, a couple winters back we were out of salt and picked up some cheapo bags at Home Depot. Ended up standing in the back of the truck pushing it through with a shovel handle. So we only use #1 Safety Salt now (bagged), and it works fine.
I've never tried bagged salt through our spreader. I think that, on average, bagged material that I have seen has been coarser material than what we often get in bulk. A mixture that has quite a lot of fines tends to bridge worse than the coarse stuff does. Before we put the vibrator on this one we would often see a hole right up the center of the hopper load, where the material had fallen straight down into teh auger but was jammed too tightly to shake loose and all fall down. That made for some pretty "iffy" spreading. The problem was worse if you had to travel very much before you spread out the load, more time for the material to pack. I think the vibe was around a couple hundred bucks, well worth it in my opinion,
I appreciate your feedback. I know exactly what condition you are describing with the material. I've not seen it in plowing since I have never plowed before, but I envision exactly what you are speaking of. I'll spend the extra money, then I don't have to worry about changing brands of salt, differences in particular lots (batches), etc.