I have used both the co-cain and the regular mineral blocks from the farm section of the local farm supply store. Sometimes the salt or mineral blocks will take time for the deer to find them (one of mine took 3 years), but after that they will regularly attend it. But remember that deer need the minerals most in the Spring and early summer. IT is during this time of year that the deer will seek out the block sites, not so much during the fall or hunting season. Another thing is that I have found that the deer would rather eat the soil (which the salt impregnated when it disolved) then eat or lick the actual block. One occasion I had the deer eat soil from under the block, causing the block to tip.

Start the mineral sites early in the year if you can to get it into the deer regular habbits. Good luck.