I've used tarsals from does for 20+ years. Its the only scent attractant I've ever had to work! Trim the fat from the flesh side, salt and keep them in the ziplocs. You'll be surprised at the ammount of scent the leaks into the bag. I never froze mine. I tied a 3 foot long string to them and drag them to where I want to shoot, tie it to a limb. The first time I tried it, I shot a doe @ 16 yards while she licked the tarsal in a tree. The buck I killed in 96 was doing the same. I haven't used the trick for the last several years simply because I quit shooting does for the most part - I always liked to kill my yearly doe toward the end of October back then as I wanted the tarsals for the rut. They last about two weeks with salt before starting to sour. Its a fun way to hunt, and very effective.