I used this many years ago when I was a kid. It does a good job at leaving leather clean & soft but doesn't give such a shiny finish as glycerine soap & doesn't smell as nice (doesn't smell bad though, just not as nice).
If the collar has gone hard & horrid you might find neatsfoot oil abetter bet & you can get it from most tack shops.
i bought this one years ago and loved it... Cleaned my tack really well.for some reason i couldnt find in the tack shop when i ran out so havnt used it
But for that price aswell you cat go too far wrong even if you dont like it!